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plant layout scientific method -which helps user to determine which lay out will be good for their industry.
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A scientific criteria for determining a good Plant Layout:1. Integration:Integrates of men, materials and machines and support services in order to get the optimum output of resources.2. Cubic space utilization:Utilization of both horizontal and vertical spaces and height is very important to use the space as much as possible.3. Minimum distance:Minimum travel of men and material should be implemented means; the total distance travel by the men and material should be minimized as much as possible. Further straight line movements should be promoted.3. Floor:Arranging the floor to move the material/finished products in forward direction towards the final stage.4. Maximizing coordination:Entry into and disposal from any department should be in such manner that it is most convenient to the issuing or receiving departments. The layout should be consider as a whole.5. Minimum flexibility:The layout should be able to modify when necessary.6. Maximum accessibility:All servicing and maintenance points should be readily accessible. For example; equipment should not be placed against a wall because necessary servicing or maintenance cannot be carried out easily. Further; equipments or other necessary units keep in front of a fuse box will impede the work of the electrician.7. Safety security:Due consideration to industrial safety methods is necessary. Care must be taken not only of the persons operating the equipment, but also of the passes-by, who may be required to go behind equipment as the back of which may be unsafe.8. Minimum handling:Reduce the material handling to the minimum. Material being worked on should be kept at working height and never have to be placed on the floor if it is to be lifted later.The following principles also can be taken in to account when planning for a good plant layout;
The geographical limitations of the site;
Interaction with existing or planned facilities on site such as existing roadways, drainage
and utilities routings;
Interaction with other plants on site;
The need for plant operability and maintainability;
The need to locate hazardous materials facilities as far as possible from site boundaries
and people living in the local neighborhood;
The need to prevent confinement where release of flammable substances may occur;
The need to provide access for emergency services;
The need to provide emergency escape routes for on-site personnel;
The need to provide acceptable working conditions for operators.
Principles of Material HandlingThese principles are guidelines for the application of sound judgment. Some principles are in conflict with others, so only the situation being designed will determine what is correct. The principles will be a good checklist for improvement opportunities.
1. Planning Principle
All material handling and storage activities need to be planned to obtain maximum overall operating efficiency. Material handling planning considers every move, every storage need and any delay in order to minimize production costs.
2. System Principle
The system concept is that all material handling equipment should work together so that everything fits. The system principle integrates as many steps in the process as possible into a single system from the vendor through your plant and out to your customers. It is to integrate as many handling activities as is practical into a coordinated system of operations, covering vendor, receiving, storage, production, inspection, packaging, warehousing, shipping, transportation and customer.
An example will be a oil company purchased plastic bottles from an outside manufacturer. The bottles were packaged in a carton of 12 with separators in between. These cartons were placed on a pallet and shipped out to the company’s oil bottling plant. In the plant, the bottles were dumped onto a filing line and filled with oil. The empty cartons was conveyed to the packout end of the filing line and repacked with 12 bottles, closed, stacked on a pallet and shipped to the customer.
3. Material Flow Principle
It is to provide an operation sequence and equipment layout optimizing material flow.
4. Simplification Principle
Using Cost Reduction Formula to simplify handling (Eliminate, combine and reduce unnecessary movement and/or equipment).
5. Gravity Principle
There are many ways to make use of gravity to move materials between workstations. Thus, utilize gravity to move material wherever possible.
6. Space Utilization Principle
It is to make optimum utilization of the cubic capacity of the warehouse. Racks, mezzanines and overhead conveyors are a few of the material handling equipments that maximize space utilization.
7. Unit Size Principle
Strength, durability, versatility, weight, size, cost and ease of use must all be considered when choosing a unit load. It is to increase the quantity, size, or weight of unit loads or flow rate.
8. Mechanization Principle
It is to add power to eliminate manual moving. Mechanization implies the use of mechanical tools to aid in the movement of material.
9. Automation Principle
Automatic storage and retrieval systems place material into storage racks automatically and remove it when needed. Many machines are automatic because material handling equipment loads and unloads the machine. Automation is the way of the future, thus even users of the manual system must consider when it can be justified. Provide automation to include production, handling and storage functions.
10. Equipment Selection Principle
In selecting handling equipment consider all aspects of the material being handled – the movement and the method to be used.
11. Standardization Principle
It is to standardize handling methods as well as types and sizes of handling equipment. Cost of material handling systems can be grouped into two categories: the cost of ownership of the system (includes the initial purchase price and the subsequent maintenance costs) and the cost of operation of the system (includes cost of training personnel to use the system safely, energy cost and other direct and indirect costs associated with the use of the system). An example will be choosing a material handling equipment and stay with that brand, type and size because spare parts inventory, maintenance and operation of this equipment will be most cost efficient.
12. Adaptability Principle
Use methods and equipment that can best perform a variety of tasks and applications where special purpose equipment is not justified. Examples will be the purchasing of standard size pallets that will handle a range of parts and purchasing of storage equipments that can store a wide variety of products. In this way, change will be less costly.
13. Dead Weight Principle
Do not buy equipment that is bigger than necessary. Tare weight refers to the weight of the packaging material. Products are packaged to prevent damage while moving. However, packaging is expensive and it costs as much as the product to ship this tare weight. Thus, the goal is to reduce the tare weight and save money.
14. Utilization Principle
Material handling equipment and operators should be used fully. Identifying the work required, the number of times per day and the time required per move will help manage the workload of both labour and equipment. Plan for optimum utilization of handling equipment and manpower.
15. Maintenance Principle
Material handling equipment must be maintained. Preventive maintenance (periodic
and planned) is cheaper than emergency maintenance. Hence, a preventive maintenance program including schedules must be developed for each piece of material handling equipment.
Pallets, storage facilities need to be repair. Missing slats on pallets can cause product damage and safety problems. Thus, plan for preventive maintenance and scheduled repairs of all handling equipments.
16. Obsolescence Principle
As equipment wears out, good maintenance records will help identify worn-out equipments. Replace obsolete handling methods and equipment when more efficient methods or equipment will improve operations.
17. Control Principle
Materials are costly and material handling systems can be a part of the inventory control system. With the aid of technology (e.g. conveyor, RFID, barcode), quality inspection, inventory control and item tracking can be incorporated into the material handling systems. It will reduce or eliminate the need to count or track the material physically. A good material handling system allows a tremendous savings in operation time and significant improved costs, accuracy and reliability. Hence, use material handling activities to improve control of production inventory and order handling.
18. Capacity Principle
Use handling equipment to help achieve desired production capacity.
19. Performance Principle
It is to determine effectiveness of handling performance in terms of expense per unit handled. Material handling labour moves material and a measurement of output could be units of materials moved. Input is labour hours. Therefore, productivity can be improved by increasing the units of material moved or reducing the labour hours.
Performance of material handling can also be calculated by ratios:Percent of Material Handling = (material handling hours)/(total labour hours)
Performance includes a lot more than labour. Segregating material handling cost from total operation costs would result in a better ratio.
20. Safety Principle
Manual handling is probably the most dangerous method of material handling. Material handling equipment can also be a source of safety problems, so safety methods, procedures and training must be part of any material handling plan. It is management responsibility to provide a safe work environment. Safety considerations must be a major factor in selecting material handling equipment. Therefore, it is important to provide suitable methods and equipment for safe handling.
Q. 1. Define Maintenance.
Ans. Maintenance refers to the upkeep and protection of plant, buildings, machinery
and other fixed assets. Maintenance engineering is concerned with keeping the physical
facilities in good operating condition. In the initial stages the quantity and quality of output tends to be good because plant and machinery is new. But after continuous use
over a period of time, machinery deteriorates due to wear and tear, stress and strain. As a result, the quantity and quality of production goes down. The deterioration of plant
the equipment may also lead to industrial accidents and other losses.
Q. 2. What are the objectives of Maintenance?
Ans. Objectives of Maintenance
The main objectives of plant maintenance are as follows
(1) to safeguard investment by minimising the rate of wear and tear
(ii) to preserve and prolong the working life of plant and equipment
(iii) to keep all the productive assets in efficient working condition
(iv) to minimise idle time and loss of production due to maintenance
(v) to maximise efficiency and economy in production through optimum use of all facilities
(vi) to minimis industrial accident through regular inspection and repair of safety
devices, etc.
(vii) to minimise maintenance costs.
Q. 3. Describe the importance of Maintenance.
Or
What is the significance of Maintenance?
Ans. Plant and equipment are the heart of production system. Therefore, proper maintenance 9f plant and equipment is essential for keeping them in good working condition. This ensures optimum utilisation of production facilities and resources. All production equipment is designed to give a predetermined quantity and quality of output. This objective can be realised only when the equipment is supported by proper
maintenance In the absence of timely upkeep, even the best machine will ultimately
breakdown. Regular use over a period of time causes wear and tear. Gears become
loose, bolts tear off, valves get checked, parts crack, pipes leak, lubrication dries, etc.
Therefore, regular inspection, lubrication, repair, etc., must be undertaken to maintain
the reliability and efficiency of equipment
Proper maintenance helps to maximise. production performance by prevcnting
breakdowns and by mmimismg the loss caused by breakdowns In a developmg country
like India mamtenance has special significance The capital is a scarce resource and its
best possible use is essential Moreover, the patural conditions like tropical climate, and
extreme humidity require special upkeep of equipment. Proper maintenance results in
better performance andlonger life of machinery. It helps to improve reliability of plant, and equipment. Maintenance is essential in all manufacturing concerns because machines breakdown, parts wear out and tools deteriorate.
Q. 4. Explain the functions and responsibilities of maintenance department.
Ans. The main functions of a maintenance department are as follows:
(i) Planning maintenance work on a long-term basis.
(ii) Issuing maintenance work orders.
(iii) Storing maintenance materials, e.g., tools, spare parts, lubricants, etc.
(iv) Deciding inspection methods and routine.
(v) Developing and issuing standard instructions.
(vi) Measuring efficiency of maintenance.
(vii) Controlling maintenance personnel.
(viii) Maintaining maintenance records.
The main responsibilities of aintenance staff are given below
(a) timely inspection and servicing of equipment;
(b) instructing proper use of equipment by workers;
(c) raising timely indent for replacement and! or spare parts;
(d) emergency repairing whenever necessary. -
Q. 5. Explain the different types of maintenance.
Ans. Types of Maintenance
Generally maintenance can be done in the following two ways:
1. Breakdown maintenance.
2. Preventive maintenance.
In the first case of maintenance, repair can be done after the breakdown occurs, while in the second case maintenance is done on the basis of prediction or on the basis of periodical checking.
BREAKDOWN MAINTENANCE
Breakdown of a machine can occur due to the following two reasons:
(1) due to unpredictable failure of components which cannot be prevent;
(ii) due to gradual wear and tear of the parts, which can be eliminated to a large extent by regular inspections, known as preventive maintenance. From experience it can be decided that, when a part should be replaced, so that breakdown can be avoided.
In breakdown maintenance, defects are rectified only when the machine cannot perform its function any longer, and the production department is compelled to call on the maintenance engineer for the repairs. After repairing the defect, the maintenance engineers do not attend the machine again until another failure.
In this type of maintenance, repair shall have to be done on failure, thus it may disrupt the hole production, if it is performing an important work. This method is much expensive also due to increase of depreciation cost, payment to idle operators, overtime to the maintenance staff for doing the emergency repairs, and idling of matching equipment.
PREVENTIVE MAINTENANCE
Preventive maintenance is sometimes termed as “planned maintenance” or “scheduled maintenance” or “systematic plant maiptenance” etc. It is an extremely important function for the reduction of maintenance cost and to keep the good operational condition of equipment and hence increases the reliability. Preventive maintenance aims to locate the sources of trouble and to remove them before the breakdown occurs. Thus it is based on the ideas “prevention is better than cure”. Scheduled maintenance is always economical than unscheduled maintenance, as we all know that,. “a stitch in time saves nine.”
Best safeguard against costly breakdown is to inspect, lubricate and check up the equipment as frequently as possible. To take full use of equipment and to maintain it in reliable condition, necessary measures should be taken to prevent overloading, dampness, negligence and misuse of machines. Frequency of inspection should be decided on the basis of the importance of the machine; wear and tear of the machine and its delicacy. This periodic inspection or checking helps to find out the reasons leading to breakdown and to rectify them, when they are in minor stages. Thus the repair can be done when one wants to do it, i.e. when it has least effect on the production schedule. Further this repair-requires lesser time as compared to that of breakdown repair and thus down time is reduced by doing preventive maintenance.
Corrective Maintenance. Although this is broadly a preventive maintenance, this term is gaining importance. While carrying out repairs on a machine, either some minor modification work is done so that it may work little better than it was working before breakdown, or some remedial action is introduced in such a way that it does not happen again, such works fall under corrective maintenance.
Q. 6. What are the objectives of preventive maintenance?
Ans. Preventive maintenance has following main objects:
1. To obtain maximum availability of the equipment by avoiding breakdowns and by reducing the shutdown periods to a minimum.
2. To keep the machine in proper condition so as to maintain the quality of the product.
3. By minimising the wear and tear, preserve the value of the equipment.
4. To ensure for The safety of the workers.
5. To keep the plant at the maximum production efficiency.
6. To achieve all the above objectives with most economical combination.
Q. 7. What are the advantages of preventive maintenance?
Ans. Advantages of Preventive Maintenance -
Following are some of the important advantages of efficiently planned and well
executed preventive maintenance programme
(i) Reduction in production downtime.
(ii) Lesser overtime pay for maintenance personnel.
(iii) Lesser number of standby equipments. are needed.
(iv) Less expenditure on repairs,
(v) Due to planned spare parts replacement, lesser spare parts are needed to remain
in store at all time.
Q. 8. Describe the functions of preventive maintenance.
Ans. Functions or Elements of Preventive Maintenance
Following are some of the important functions of the preventive maintenance
programme: . -
1. Inspection or checkups.
2. Servicing including cleaning, cooling and lubrication.
3. Planning and scheduling.
4. Records and analysis.
5. Training to maintenance staff.
6. Storage of spare parts.
1 Inspection or check-ups. Inspection is an essential function of the preventive
maintenance programme. Crews kept for this purpose should be well-trained. These
crews carry out both the external and internal inspection. External inspection means to
watch for and detect defects from abnromal sound, vibration, heat, smoke etc. when
machine is in operation; while internal inspection means inspection of internal parts,
such as gears, bushes, bearings, tolerances in the parts, etc., during the period when the machine is under pre-planned shutdowns. -
Frequency of inspection should be decided very carefully, as too less inspection may
cause breakdown, as defects cold not be traced out and rectified immediately; while too
muèh inspection means wastage of machine time and labour productivity. Hence, frequency should be decided on the basis of past experiences and the scheduled
programme for inspection is chalked out.
For the purpose of inspection machines can be categorised as: .
(i) Important machines. These are those machines which can disrupt whole of the production, are delicate andrèquire much time for the repair. More stress should be given for the inspection of these machines, and schedule for inspection, cleaning, lubrication, should be followed too rigidly.
(ii) Ordinary machines. Frequency of inspectibn can be kept as low as they do not
effect the production considerably. -
2. Servicing. Mechanical components like gears, bearings, bushes and other friction surfaces etc. give good performance for long periods, when -they are systematically lubricated. Systematic lubrication means the application of right type of lubricant at the right time, at the right place and in right quantity. For servicing a lubrication schedule should be prepared and followed strictly. Servicing includes cleaning, lubrication and check-ups. - -
3. Planning and Scheduling. Every preventive maintenance work should be pre-
planned in detail on the,basis of the analysis done on the past records. A scheduled
programme thus prepared should be followed strictly. Thus programme should be in
detail specifying the points requiring daily, weekly, ‘monthly, half yearly or yearly attention. Recommendations of the ecjuipment manufacturershould also be kept in view.
4. Records and Analysis. Good record keeping isessential for good preventive maintenance as it helps in forecasting maintenance. For this purpose following records ar generally, maintained (i) Operation manual, (ii) Maintenance Instruction manual, (iii) Histoiy Cards and History Registers, (iv) Spares Procurement Register, (v) Inspection
Register, (vi) Log books, (vii) Defects Register etc. With the help of these records possible cause for major repetitive failures àan be examined aiIZI - rectified so as not to repeat so early. -
These records helps the Managers to take decisions and plan maintenance. The analysis
made on the basis of these records helps in —
(i) Preventing defects rather than rectifying after breakdowns.
(ii) Knowing the.machines reliability and thus helps in production planning.
(iii) Deciding life of the machine.
(iv) Forecasting defects and planning to rectify them before the failure occurs.
(v) Frequency of inspection and check-ups. -
(vi) Deciding for the purchase of a machine, which may suit best, on the basis of.past
experience. •-
In spite of best inspectióh and other measurs failures are bound to occur but they
can be reduced to large extent, by planned maintenance.
5. Training of Maintenance Personnel. For the success of preventive maintenance a sound training is essential for the mamtenance personnel Hence the technicians and supervisors are trained to carry out maintenance, inspection and répairs in a systematic
way.
6. Storage of Spare Parts. Sometimes machine remains idle for want of spare parts
for a considerable time and thus it affects considerable loss of production. Hence it is
essential to keep the spare parts sb as to avoid loss of production. But the judgement and
experience of high order is required for deciding the number of such parts, as storage of
a large number of parts will mean blocking of capital. The level of spare parts must be determined by considering different factors such as source of supply, defivery period
and availability of that spare part in the market.
Standardisation will help to reduce the spare parts inventory and will also help in specialisation of maintenance of particular type of equipment.
Q. 9. What are the requirements of good preventive maintenance?
Ans. Requirements of good Preventive Maintenance
For achieving preventive maintenance of high order, following are some of the essential requirements
1. Good supervision and administratiOn of maintenance department.
2. Correct, clear and detailed instructions be given to the maintenance crew and to
the operators.
3. Operators should be well-trained.
4. A good lubrication programme should be chalked out.
5. Proper maintenance records should be maintained.
6. Adequate stock of spares should always be kept.
7. Manufacturers of the machine tools should be consultediis and when required,
8. Maintenance department should remain in contact with planning and purchasing
department in deciding the type of machine to be purchased. Aniachine to be purchased
should be of best design, adequately safe, with good lubrication arrangements, minimum
of moving parts, easy availability of spares etc.
9. Standardisation on types of equipment deployed to control inventory and to have
specialisation.
10. Use mobile service vans.
11. Establish well equipped service/repair shops.
12. While transferring a machine from one project to another, it is better to repair first and then transfer, as sending project knows the equipment better.
Q. 10. What is Integration?
Ans. Every organisation; large or small, should have a well-considered induction
programme. However, designing an appropriate and cost-effective induction package is a complex task. The induction programme has to provide all the information that new
employees and other need, and are able to assimilate, without being overwhelming or
diverting them from the essential process of integration into a team. The term ‘induction’ is generally used to describe the whole process whereby employees adjust or acclimatize to their jobs and working environment.
Q. 11. Discuss the stages in planning work of maintenance.
Ans. As we know that preventive maintenance work can be anticipated and planned. This reduces the uprecedented breakdowns and keeps the machine in reliable condition.
Therefore it is always adviséable to plan the maintenance work for taking lesser time for preventive maintenance and make it more effective. Maintenance work can be planned
in following stages:
(a) Anticipation of maintenance work. Maintenance work can be anticipated with
the help of (1) Instruction of manufacturer of the machine (ii) experience of the
maintenance and production personnel (iii) utilisation on the machine and its place of
application (iv) Behaviour of the machine du its operation.
(b) Visualising the work to be undertaken in future. By way of interaction between maintenance and operation personnal about the nature of trouble experienced and inspection of the machine will indicate the type of attention required. This will enable the maintenance crew to plan for material, man power requinrd to attend the machine.
(c) Determination of method to perform the work. In the next stage a decision is taken to determine the effective method to perform the work.
(d) Scheduling work. In order to get machine free from production work for a minimum period of time, maintenance work is required to be scheduled. Scheduling of maintenance work is done considering the importance of ñachine for production work.
Maintenance department should therefore prepare a schedule of maintenance work in all the departments for all the machines, and intimate the concerned department well in advance, so that these machines are spared by them with sudden interruption of work.
(e) Instructions to individuals. Each concerned personnel connected with the execution of work should be instructed about the work to be done by them, method to be adopted, maximum time to be taken (i.e. scheduling), time to start the work.
(t) Follow-up and check-up The work being executed should be followed as per plan. Proper checks about quality and timely progress be exercised.
(g) Evaluation of work. Work cost, time taken, condition of worn parts with reference to their life should be compared with respect to past data. Proper record keeping should be ensured.
Q. 12. To what extent expenditure should be done on maintenance from economic point of view. Discuss in detail.
Ans. Extent of preventive maintenance should be such that it may not become uneconomical. For this purpose cost of breakdowns and cost of scheduled maintenance are to be studied. This cost should include expenditure of idle niean, cost of idle machine, spoilage etc. It is natural that when
the cost of scheduled maintenance increases, the cost of breakdown decreases But after some extent, increase in the expenditure on scheduled maintenance becomes uneconomical. For this purpose these two costs should be plotted in a graph and cumulafive costs of both types of maintenance are superimposed in this graph, as shown in the following Fig. 10.1 from which an optimum point can easily be determined, which gives - the quantum of maintenance.
From the economic poit of view, it is also necessaiy to decide the quantum of inspection very carefully on the basis of past experience and records analysis as explained earlier. As over inspection costs more and results in large loss in production time while under inspection results in more breakdowns.
Care should also be taken, while preparing maintenance programme so that as far as
possibleinspection and lubrication schedule should coincide, so that machine idle time
and production disruption maybe less. Inspection and lubrication schedules must be
communicated to the production department, so that it may be able to free the machine
as per programme.
Q. 13. Describe structure of Maintenance organisation.
Ans. A sound organisational setup is necessary for effective administration of
maintenance activities. A tailor-made organisation should be developed keeping in view
the volume and nature of the maintenance work. Every individual should be entrusted
with a well— defined maintenance assignment for which he is qualified. The head of the
maintenance department should be made responsible to the head of the production or
works department. The person incharge of the maintenance function is generally called
plant engineer or maintenance engineer. The maintenance personnel should have sound
training and specialisation. Definite lines of authority and responsibility should be
established between the ainfetiance group and other concerned groups. A typical
organisation for maintenance work is given below:
The organisation structrüe for maintenance may be centralised or decentralised, In centralised setup, all maintenance requests are directed to a central maintenance section
which sends suitable team. Under decentralised set up, all major production departments
or plants are assigned maintenance crews according to the volume of work and degree
of specialisafion. In addition, there is a central grup responsible for coordination of decentralised groups, stores, machining operations and administration. The choice between the two setups depends on the local conditions and requirements. Maintenance department is primarily a service department.
Q. 14. What is the effect of maintenance on productivity.
Ans. Productivity of a plant depends upon effective and regular utilisation of production facilities. Proper maintenance of plant and equipment helps to raise productivity by minimising breakdowns and idle resources. Periodic checkup prevents avoidable interruptions in operations. Planned overhauls and quick repairs of machinery
result in better utilisation of resources. Regular maintenance increases working life of
machine and leads to greater utilisation of plant. Improved production economy results
in lower unit costs. By minimising the rate of deterioration need for fresh capital to
replace worn out machinery is reduced. The capital thus saved can be utilised for
expansion of plant utilities and employee services.
Q. 15. Describe maintenance effectiveness
Ans. Efficient measurement and control of the effectiveness of a maintenance
programme is required to achieve the objectives of maintenance. The effectiveness of
maintenance can be evaluated in terms of the maintenance costs, downtime, etc. An
information system is required for gathering data about costs and downtime. The purpose
of the system is to generate information for management guidance and control. Work
requests, work orders and material requisition are sub-systems of maintenance system.
Several indices have been developed for measuring maintenance effectiveness. These
indices are computed on the bass of information relating to
(a) Cost of maintenance
(b) Available machine hours and downtime;
(c) Number of breakdowns;
(d) Labour hours spent on both breakdown and preventive maintenance,
Indices may be:
The indices or planning indicators which need to be improved from year to year
include per cent of emergency work, per cent of jobs completed on schedule and per
cent of maintenance hours planned.
Q. 16. What is tera technology?
Ans. The concept of tera technology originated in the mid-sixties. It stresses the need
fd maintaini,ng physical facilities for efficient operation of any manufacturing concern.
Tera techi’iology refers to the technology of installing, comixuss1onmg, maintaining and
replacmg of plant and equipment It also covers feedback of operations and design
experience and the related practices. Under it, an amalgam of managerial, financial,
engineering and other related practices is applied to physical assets
Q 17 What are the losses due to poor maintenance?
Ans. In the absence of proper, repairs and maintenance, the following types of losses
may arlsç:
1. Lower productivity. DeteriOration of plant and equipment results in frequent
interruptions or breakdowns which in turn leads to production loss. Such loss is very
high in capital-intensive and continuous process industries.
2. HIgher costs. Every interruption in production means cost of idle equipment and
wages of idle labour. There is greater wastage of materials and parts. Incompetent and
inadequate maintenance results in increase in unl(cost of manufacturing
3. Poor product quality. Undetected and uncontrolled wear and tear of machinery
results in deterioration of product quality. It is not possible to maintain the standards of ‘
workmanship .
4. Destruction of equipment. When the equipment is allowed to deteriorate beyond
repair, the life of machines is reduced. Overuse and careless use of machines cause premature
replacement of capital assets. Indian industries suffer from an unduly high rate of depletion
of capital assets and a chronic waste of production capacity on account of inadequate
maintenance. Very often the need for maintenance is not felt until the machine actually
breaks down. Cost of maintenance is considered an unnecessary expense rather than an
investment. Attempt is made to avoid or postpone maintenance expenditure. Lack of proper
maintenance practices serves as a constraint in the economic development of the country.
5. Induced loss. Production loss in one plant leads to negative consequences for both
the customers and suppliers. When a plant supplies poor quality intermediate goods
additional processing is required or the quality of the final product deteriorates. Frequent breakdowns result in irregular deliveries. In order to ensure uninterrupted production in
•the face of unstable supplies, the firm has to keep high stocks of intermediate components and spare parts. This is an unnecessary locking up of scarce capital and waste of resources.
6. Disguised loss. When an ill-kept machine breaks down, the plant switches over to an idle equipment to avoid disruption in production. In an industry where installed capacity is underutilised this may give the impression that excess capacity is being utilised. But in reality there is disguised poor maintenance. Similarly, the poor quality products may be easily sold if there is a serious shortage of supply. In a seller’s market consumers have to accept whatever quality is available at whatever time. The deterioration in quality and delays in delivery are disguised.
7. Poor customer relations. When the quality of product is poor and delivery schedule is not maintained, relations with customers will deteriorate. This will lead to a permanent fall in sales turnover and loss of market.
8. Poor staff morale. Employees lose enthusiasm and interest in work, when the machine or equipment frequently breaks down.
The losses and waste caused by poor maintenance impair economic growth in
developing countries like India where the resources are limited and industrial sector is
comparatively small.
Q. 18. What is induction and its elements?
Ans. The purpose of induction is to ensure the effective integration of staff into or
across the organisation for the benefit of both parties. Research has shown that tailorinor
made induction programmes increase staff retention. A good induction programme
contains the following elements:•
Orientation (physical) — describing where the facilities are
• Orientation (organisational) - showing how the employee fits into the team and
how their role fits with the organisation’s strategy and goals
• Health and safety information — this is a legal requirement
• Explanation of terms and conditions.
• Details of the organisation’s history, its products and services, culture and values
• A clear outline of the job/role requirements.
Q. 19. Explain the induction process.
Ans. The structure of ari induction course depends not only on the size and nature of
an organisation but also on the type of recruit. The process begins at the recruitment
stage and continues into employment. New recruits need to know the organisation, the
culture and the people, and their role Ideally, all new employees should receive an
individual mduction programme that reflects their specific needs For a large company,
this programme would be a combination of one-to-one discussions and more formal
group presentations, which may be given within an induction course.
The line manager is responsible for a new recruit’s induction, but would not be
expected to cover all the elements personally. Atypical allocation of induction tasks could be:
• Line manager/supervisor : explain the departmental organisation, the requirements of the job, the purpose and operation of any probationary period
and the appraisal system.
• HR cover the housekeeping aspects for a new starter such as completing employee forms, taking bank details, explaining the induction programme.
• Safety officer explain health and safety issues.
• Section supervior or a nominated colleague provide an escorted tour of the department and introduce fellow workers; then give day-to-day guidance in
local procedures for the first couple of weeks.
• Senior manager(s) and/or HR: give an overview of the organisation, its history, products and services, quality system and culture.
• Training officer (or line manager) describe available training services, then help to develop a personalized training plan Provide details of other sources of information during induction such asthe company intranet or interactive learning facilities.
• Company representatives from trades unions, sports and social clubs, etc give details of membership and its benefits.
• Mentor or 4buddy’ : sometimes inductees are allocated a colleague, not their immediate line manager or anyone from the personnel function; to help speed
up the settling-in period.
Q, 20. Advantages and disadvantages of Induction Program.
Ans. Advantages
• Saves inductors’ and managers’ time by dealing with a group rather than several individuals.
• Ensures that all new recruits are given a positive message and consistent information.
• Can employ a range of communication techniques including:
* group discussion and projects
* presentation (Power Point/ overheads/slides/videos)
* visits and guided tours,
* off-site training sessions
* involvement with suppliers; customers and contractors.
• Enables new recruits to socialize with each other.
• Is relatively easy, to arrange.
Disadvantages
d Contains a range of subjects that are unlikely to appeal to a cross-functional and mixed ability group of new employees.
• May take place several weeks, or even months, after the inductee joins the organisation, which disrupts integration into the work team.
• Is less personal and involves managers and HR personnel rather than colleagues and local supervisors.
• Contains too much information to be assimilated in a short time.
• May not be a true reflection of either the organisation or the job.
• individuals may not be able to attend all sessions in a series of induction presentations resulting in incomplete induction.
Productivity-Standard of living;
Standard of living
• The extent to which a person is able to provide the things that are necessary for sustaining and enjoying life.
• Standard of living of a representative family differs greatly in different parts of the world.
• What is considered a necessity in one part of the world could be considered a luxury in the other.
• Basic necessities of a minimum decent standard of living: Food, clothing, housing and hygiene. Also, security and education also considered constituents.
• Greater the amount of goods and services produced in any community, the higher its the average standard of living.
• There are two ways of increasing the amount of goods and services produced:
- Increase the employment and investment in creating jobs. So that more people are producing goods required for the society.
- Increase productivity. Same amount of labor produces more goods.
We want:
• More and cheaper food by increase in agricultural productivity
• More and cheaper clothing and housing by increased industrial productivity
More hygiene, security and education by increasing overall productivity
Method of improving productivity.
• Process planning – Identification of correct machines for the process. In chemical industry, this is specified by the R&D division or the license seller.
• Process research – Identification of best manufacturing technique.
• Proper maintenance.
• Method study – Combine with process planning to give most suitable tools for the operative. Includes factory layout, working methods of the operative.
• Operator training – Improve working methods of the operative.
• Strategic decisions – Which markets to enter can affect ineffective time to a great extent.
• Production planning – It is planning of proper programs of work so that plant and workers are kept supplied without having to wait.
• Proper programs should be applied only on the basis of sound standards of performance.
• Work measurement – Setting up those standards.
• Material control – Workers and machines should not be idle because of non-availability of material and tools.
Training.
• Make worker want to reduce ineffective time. (Create conditions to make the worker get on with his work. Hawthorne effect)
• Effective personnel policy and management’s attitude towards the worker.
• Good relationship between management and worker.
• A sound wage structure, including incentive schemes (typically based on time standards derived from work measurement).
Work StudyDefinition by ILO: Is a generic term for techniques, particularly method study and work measurement,
which are used for the examination of human work in all its contexts, and which lead systematically to
investigation of all the factors which affect the efficiency and economy of the situation being reviewed, in
order to seek improvements.
Work study investigates the work done in an organization and aims at finding the best and the most
efficient way of utilizing the available resources (man, material, money and machinery) to achieve best
possible quality work in minimum possible time.
- which involves least possible time and causes least possible fatigue to the worker
Method study or Motion study
Method Study is the systematic recording and critical examinaton of existing and proposed ways of doing
work, as a means of developing and applying easier and more effective methods and reducing costs.
Work StudyAreas of Application
The application of methods engineering may be required in a variety of circumstances.
It ranges from the design of a new plant, to the design of a new product, to the design of
a new process, to the improvement of an existing process, to the improvement of an
existing workplace. Wherever work is being done, methods engineering is a desirable
function to ensure that the work is being done in the easiest, safest, and most
productive way.
Origin of Methods Engineering
Methods engineering grew out of the pioneering developments of the Gilbreths (Frank
B, and his wife, Lillian M.) who developed many of the tools of “motion study” as a part
of formulation a systematic approach to the analysis of work methods. Frank B Gilbreth
first become interested in methods analysis as an outgrowth of his observations of
brick-laying.
Gilbreth, who in 1885 was employed as an apprentice bricklayer, soon observed that a
journeyman bricklayer used one set of motions when laying bricks slowly, another set
when working at average speed, and still a different set when working at rapid speed.
As a result of his observations, he invented an adjustable scaffold and developed a set
of motions that greatly increased the number of bricks that could be laid in a day.
Organization for Methods Engineering
As indicated previously, methods engineering is a necessary function to ensure that the
most efficient methods are being used. This activity is most frequently performed by
industrial engineers; however, all engineers should be concerned with work methods.
The engineers may be assigned to a central methods engineering or industrial
engineering department or may be assigned on a decentralized basis to specific
operating departments.
Some multiplant companies maintain both a central industrial engineering group to work
on problems common to many plants and also assign engineers to each plant to work
on projects pertinent only to that plant.
Approach to Methods Design
Charles E. Geisel States that in order to design a system (method) thoroughly, eight
elements must be considered.
1. Purpose: The function, mission, aim or need for the system.
2. Input: The physical items, people, and/or information that enter the system
to be processed into the output.
3. Output: That which the system produces to accomplish its purpose, such
as finished steel, assembled toasters, boxes, and so forth.
4. Sequence: The steps required to convert, transform, or process the input
to the output.
5. Environment: The condition under which the system operates, including
physical, attitudinal, organizational, contractual, cultural, political, and legal
environment.
6. Human agents: The people who aid in the steps of the sequence without
becoming a part of the output.
7. Physical catalysts: The equipment and physical resources that aid in the
steps of the sequence without becoming part of the output.
8. Information aids: Knowledge and information resources that aid in the
steps of the sequence without becoming part of the output.
To ensure that the optimum method is found, a systematic approach to methods design,
superior to the use of a ‘hit or miss’ method, is used. Stated in simplest form, this
approach consists of the following steps:
1. Analyze the problem: Identify the problem and then secure all known
information about it through the use of appropriate analysis techniques.
2. Question are present method. If a method presently exists, question the
details of the known information to determine the principles violated.
3. Synthesize a proposed method: Formulate a proposed method for
performing the work, embodying all the principles of sound methods
engineering.
4. Apply the proposed method: Standardize and apply the new method.
Tools for Methods Analysis
Name of Chart Where Used
Flow Process Macro analysis; shows big picture of a production process
operation by operation; may be performed by visual
observation.
Operation – right and left- Micro analysis: Shows steps performed by a worker within
hand an operation; may be performed by visual observation.
Simo- simultaneous Fine micro analysis; uses threbligs for a very detailed
motion chart analysis of human motions; usually makes use of videotape
or motion pictures.
Multiple activity – worker Macro; may involve machines or several workers and time
and machine or crew is of significance, may be performed by visual observation
and/or videotape.
Process ChartHarminder Singh Hundal
A flow process chart is a graphic symbolic representation of the work performed or to be
performed on a product as it passes through some or all of the stages of a process.
Typically, the information included in the charts is quantity, distance moved, type of
work done by symbol with explanation, and equipment used. Work times may also be
included.
Right and Left – Hand Operation Chart
Symbol Name Activities Represented
Operation Modification of object at one workplace. Object may be
changed in any of its physical or chemical
characteristics, assembled or disassembled, or
arranged for another operation, transportation,
inspection, or storage.
Transportation Change in location of object from one place to another
Inspection Examination of object to check on quality or quantity
characteristics
Delay Retention of object in a location awaiting next activity.
Not authorization is required to perform the next
activity.
Storage Retention of object in location in which it is protected
against unauthorized removal.
Multiple Activity Chart
In those operations involving the combination of a person and a machine, a person and
several machines, or any combination of people and machines where delays are
prevalent, the multiple activity chart provides a convenient technique for analyzing the
combined activity. Very often the objectives of this type of analysis are to attain the
maximum utilization of a machine, to attain the optimum person to machine relationship,
or to bring about the best balance of crew activity.
For this reason, the time factor is an important consideration and necessitates the use
of a graphical representation involving time.
Use of Videotape
In the past, the experienced methods engineer found that one of the most important
aids was the use of motion pictures. There are many situations in which it is difficult to
observe all of the action taking place because of the high speed of activities or the
complexity of the operation.
Having observed slow-motion motion pictures, we are familiar with the fact that one can
take motion pictures at high speed and then, by projecting them at normal speed, slow
the action down. By the same token, we can take the pictures at slow speed and project
them at what appears to be high speed.
In using motion pictures, methods engineers may have had several objectives in mind.
First and foremost, they may have wanted a permanent record of the work as it was
being performed. Or they may have wished to use the film for analysis purposes,
commonly referred to as “micromotion” or “memomotion” studies, discussed in some
detail in sections that follow.
Micromotion Study
Micromotion study, which was originated by Frank B. Gilbreth, is one of the most
exacting forms of work analysis available for job improvement. It is an analysis
technique making use of motion pictures (or videotape) taken at a constant and known
speed. The film becomes a permanent record of both the method being used and the
time consumed in doing the work.
Although micromotion study formerly made use of motion pictures, very few companies
today are using them. As indicated earlier, videotape equipment has been developed so
extensively that it has virtually supplanted the use of the motion picture camera. Further
it is so cheap and easy to use that it makes the older approach archaic.
Micromotion study provides a valuable technique for making minute analyses of those
operations that are short in cycle, contain rapid movements, and involve high production
over a long period of time. Thus it is very useful in analyzing operations such as the
sewing of garments, assembly of small parts and similar activities.
Memomotion Study
Before leaving the general area of micromotion study, let us touch briefly on
memomotion study. Memomotion study, which was originated by M.E. Mundel, is a
special form of micromotion study in which the motion pictures or videotape are taken at
slow speeds. Sixty and one hundred frames per minutes are most common.
Memomotion study has been used to study the flow and handling of materials, crew
activities, multiperson and machine relationships, stockroom activities, department store
clerks, and a variety of other jobs. It is particularly valuable on long-cycle jobs or jobs
involving many interrelationships. In addition to having all of the advantages of
micromotion study, it can be used at relatively low film or tape cost (about 6% of the
cost at normal camera speeds) and permits rapid visual review of long sequence of
activities.
Principles of Motion Economy
Through the pioneer work of Gilbreth, Ralph M. Barnes and other investigators, certain
rules for motion economy and efficiency have been developed. Some of the more
important of these principles are the following:
1. The movements of the two hands should be balanced and the two hands
should begin and end their motions simultaneously.
2. The hands should be doing productive work and should not be idle at the
same time except during rest periods.
3. Motions of the hands should be made in opposite and symmetrical
direction and at the same time.
4. The work should be arranged to permit it to be performed with an easy
and natural rhythm.
5. Momentum and ballistic-type movements should be employed wherever
possible in order to reduce muscular effort.
6. There should be a definite location for all tools and materials, and they
should be located in front of and close to the worker.
7. Bins or other devices should be used to deliver the materials close to the
point of use.
8. The workplace should be designed to ensure adequate illumination,
proper workplace height, and provision for alternate standing and sitting
by the operator.
9. Wherever possible, jigs, fixtures, or other mechanical devices should be
used to relieve the hands of unnecessary work.
10. Tools should be prepositioned wherever possible in order to facilitate
grasping them.
11. Object should be handled, and information recorded. Only once.
Job Enlargement and Enrichment
This has led to the contention of a number of social scientists that hobs need to be
enlarged or enriched. Feedrick Herzberg, one proponent of job enrichment, feels that
the purpose of job enrichment should be to eliminate the undesirable characteristics of
highly repetitive, specialized work by enlarging it to include:
1. Greater variety of knowledge and skill
2. Giving a person a complete natural unit of work (module, division, area,
etc.)
3. More complex utilization of the important cognitive and motor abilities
possessed by the worker.
4. More freedom and responsibility in the performance of the tasks at hand.
Among the principles that commonly are applied in job enrichment programs, the
following are attended to by one large company.
1. Ensure that there is variety in the job content.
2. Include in the work situation an opportunity for the worker to grow and
learn.
3. Provide an opportunity for each worker to have knowledge of the part that
his or her job plays in the total manufacturing process required to produce
the product.
4. Design the work so that it has meaning to the worker and provides pride in
performance to the worker.
5. Ensure that the work is reasonably demanding and functionally inclusive.
Provide for self-direction of the work and for the checking of quality of
output.
Value Analysis
As a part of the approach to methods improvement, the methods engineer should
question the impact of the design of the parts, the materials used, and the equipment
used on the productivity of operations. That is, the methods engineer should be
thoroughly familiar with value analysis, an activity that is closely both to the methods
improvement programs and to purchasing and that is being used extensively in industry
and the government.
Value analysis is an objective study of every item of cost in every component part,
subassembly, or piece of equipment. This includes a study of the design, the material,
and the process in a continual search for other possible materials and new processes.
Value analysis involves the evaluation of an items function and relates its effect to the
end product. The purpose is to attempt to ensure that every element of cost contributes
proportionately to the function of the item.
Social and Economic Effects of method Study
As pointed out at the beginning of this chapter, modern industry is constantly searching
for better methods. When a business ceases to move forward, it will lost ground and
may eventually fail. It is for this reason that the major companies have organized
industrial engineering groups, work simplification and value analysis programs,
suggestion systems, quality circles, and other methods of achieving reduced costs of
manufacturing their products.
One of the consequences of these programs has been increased mechanization, which,
in turn, has led to the production of more and more goods per work hour. Among the
long-range benefits derived from this increased output have been higher real wages, an
improved standard of living, a shorter work week, and a reaction of the physical rigors of
the job.
--
Work Measurement or Time study Edit
Method Study – Systematic recording & critical examination of the way of doing a work as a mean for
developing more effective methods & reducing costs.
Work Measurement – Establishing the time required by a qualified worker to carry out a specified job at a
defined level of performance
Steps in Method Study - :
Select job or process to be studied
Record All the details concerning job
Examine Recorded facts Develop Most economical method
Define New method
Install New method
Maintain New method
Recording Techniques - :
1. Process Charts
1. Outline Process chart (or operation process chart)
2. Flow Process chart (Man type; Material type; Equipment type)
3. Multiple activity chart
4. Two handed process chart (or Left hand-Right hand chart)
5. SIMO chart (Simultaneous Motion Cycle chart)
2. Diagrams
1. Flow diagram
2. String diagram
3. Cyclegraph
4. Chronocyclegraph
3. Models
i) Outline Process Chart – Gives bird’s eye view of the process; considers only main operations and
inspections
ii) Flow Process Chart – Detailed version of operation process chart shows the "OTIDS" Operation
(transforms or performs work that the customer may see as Value which is the product or service
Function at a Cost); Transport/Move; Inspection/Check; Delay/Wait and Store/File. Recent "OTIDS" have
adde anoth D being Decision to become "OTIDDS". The use of "Value Stream Maps" in "Lean" (John
Krafcik a research student at MIT in late 1980's) are enhanced for each major step in the Value Stream
by using the Flow Process Chart to provide more details on the value and non-value activities in the
Stream. Value Analysis/Value Engineering and Process Failure Mode and Effect Analysis techniuques in
the Automotive qualkity and technical specificvation (ISO TS16949:2002) and Boeing Aircraft Corporation
Quality Tools Manaul all use Flow Process Charts
Person type – Sequence of activities performed by worker
Material type – Sequence of activities performed on material
Equipment type – Sequence of activities performed by equipment
iii) Multiple Activity chart – Activities of more than one man or machine are recorded on a common time
scale
iv) Two handed Process chart – Activities performed by two hands of worker are recorded on a common
time scale
v) SIMO chart – Detailed version of two handed process chart (micromotion study)
vi) Flow diagram – Shows the relative position of machines and equipments and marks the path followed
by man and material
vii) String diagram – similar to flow diagram except that path is traced by a continuous string or thread
viii) Cycle graph – To study the path of movement of operators hands;
A small electric bulb is attached to hand and photograph is taken by a still camera
ix) Chronocycle graph – Similar to cycle graph except that along with path it also shows direction and
speed of movement. This is done by interrupting the light source so that path appears as a series of dots.
SIMO chart is Micromotion study whereas
cycle graph and chronocycle graph are Memo Motion Study
Memo Motion study involves time-lapse photography ie a still camera takes pictures of the activity at
regular intervals (1 to 5 sec) unlike micromotion study which involves making a continuous motion film
Memo motion study is used for activities which are not required to be examined in fine detail but are still
too fast to be recorded accurately by human eye.
Therbligs – are the fundamental hand motions which are performed over and again in any manual work,
eg Search, find, select, hold, grasp, use, assemble, dissemble, inspect, release
-developed by Mr. Gilbreth (Therblig is his name spelled backward) -used in micromotion study
Work Measurement
Std. time for any job may be established by 3 methods:
Time Study (stop watch) Short cycle ; Repetitive jobs Work Sampling Long cycle ; Heterogeneous
operations PMTS Short cycle ; Highly-repetitive jobs
Work sampling
Time
study
Synthetic time
P.M.T.S.
Analytical
estimating
Direct
Indirect
Work
Measurement
Work Sampling
In this a no. of observations are made over a period othat instant. The percent of observations
recorded for a particular activity is a measure of the percentage of time during which that activity
occurs.
Work Sampling is used for activities of very long duration which cannot be measured with stopwatch. Eg
to find out actual working time of an operator in one shift.
It is based on Statistical theory of sampling – ie adequate random samples of observations spread over a
period of time can construct an accurate picture of the actual situation of system.
No. of observations required for 95% confidence level and ±5% accuracy (ie we are sure that 95% of the
time the average value will not be having error more than 5% of the true value.
N = 4p(100-p) (p = percent of occurance)
--------------- (A = Accuracy required)A2
StopWatch TimeStudy
Why do we break down the activity to be studied into elements?(why not measure time straightly)
To provide a detailed work specification
To separate value adding & non-value adding activities
To select best method by comparing work elements of different methods
Stopwatch – one revolution = 1 minute (1 deciminute = 1/100th of minute)
Normal time = Observed time * rating factor
Standard time = Normal time + allowances
Rating – Comparing the pace rate or performance of a worker against standard performance level
to take into account different operators’ performance level
Rating techniques-
Speed- Worker’s speed/speed expected
However assigning a rating factor and allowances are largely subjective in nature and depends on
personal judgment of timestudy engineer
Allowances- it is the additional time provided over and above normal time to take into account time for
relaxation, attending personal needs
Rest and personal allowances (to overcome fatigue incurred during working)
Interference allowances (to take into account m/c stoppages etc)
Special allowances (for activities which are generally not a part of work cycle)
In this we build up the total time for a job by summing up the times for different elements
Particularly useful for operations which are still in the planning phase and have not yet started
(helpful in planning and scheduling)
Synthesis
PMTS (Predetermined Motion Time System)
Analytical estimating
Synthesis
Element time values are taken from a catalogue of elements time built from timestudies done in
the past
PMTS also make use of previously collected data but it deals with basic human motions (or therbligs) of
duration 0.1 seconds or less. Whereas in synthesis duration may be 3-4 seconds
Analytical estimating is used when past time data is not available and estimator has to rely on his past
experience.
PMTS
For short cycle & highly repetitive jobs
Uses video film (micromotion study)
More accurate than stopwatch timestudies
No rating factor required but allowances need to be added
But can deal with only manual motions of the operation
Method Time Measurement
Work Factor Systems
1 TMU = 0.0006 minutes (TMU = Time Measurement Unit)
1 wink = 0.0005 minutes (used in SIMO chart/micromotion study)
Analytical Estimating
For long and non-repetitive operations ; Least accurate
(Machine elements – calculated from information of feed, speed, depth of cut etc)
Comparison
It is difficult to compare different work measurement techniques, as each technique has its own set of application
Work sampling is used for long cycles eg amount of time actually spent working by a worker in a shift
Time study is used for short repetitive cycles eg worker working on a assembly line
'''Bold textPMTS is used for very short cycles which require a very detail analysis (micromotion
study)
Time
study
Work sampling
Synthetic time
P.M.T.S.
Analytical
Time Required
MAX
MIN
Accuracy
MAX
MIN
TIME & MOTION STUDY : A NEW PARADIGM
In theory there is no difference between theory and practice,In practice there is …….
I realized it by myself when I undertook a project on time & motion study during my summer internship. On paper it looks very easy to do timestudy with a stopwatch. But when you actually do it you realize the practical difficulties associated with the traditional method.stung
That’s why I picked up the cause in my final year project and developed a software which automates the
process of time & motion study.
