Common Automation Process System and Ergonomics Research study

-CASPER

Project AFM212Br, completed

by INBIS, Loughborough University (Ergonomics and Safety Research Institute),and University of Salford

September 2003 – April 2004

Patrick Williams – MSc, MRAeS, MCMI– Casper Project Manager, INBIS

CASPERIntroduction

The Casper programme was defined between INBIS and Marks and Spencer following the success of the ASAP AFM 173 R&D programme, and concerns with ergonomic issues in the food assembly sector.

Developed in to AFM212Br with DEFRA.

Objectives

1. To consider whether more common automation techniques can be applied across a wider area of the food production/assembly sector

2. Complete a limited Evaluation of the ergonomics issues in food production/assembly operations and consider the implication for the sector

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Supply chainMarks and Spencer identified the following organisations where

maximum benefits may be possible :• Gunstones – Bakery and filled roll production• RHM – Avana Cake decoration• Tulip – Meat slicing• Uniq PFF - Salmon processing

Deliverables• Individual company assessment reports for use within the

companies.• Report on ergonomics issues in the sector, and common

automation opportunities, and a proposal for progressing these.

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AnalysisTwo distinct analysis processes :

Automation• Evaluation of current processes, • Assessment automation techniques currently available, • Assessment against new technology, • Consideration of operational scope of robotics/mechatronics,• Process assessment using ‘Lean Thinking’ 5S methods

(Automotive/Aerospace industry), for more effective and efficient operations.

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Ergonomics –

• Observation/video of worker motions and evaluation using Rapid Upper Limb Assessment (RULA) (McAtamney and Corlett, 1992 and 1993) techniques, for physical strain and discomfort, and impact due to repetitive motion.

• Reach, and height dimensional assessment against ergonomic standards

• Interviews providing supporting evidence on physical comfort, and non physical aspects of repetitive work, • Assessment of worker and management interaction in the design of

processes.• H&S perspective and formal records for Work Related Upper Limb

Disorders (WRULD’s).

CASPERFindings - roles

• Differing product lines, but various common themes in operation.• High manual content in 3 of the lines assessed out of the 4.• Various types of manual function

– Skilled critical part of the production process, cannot be replaced by automation without an impact on yield, long training periods to acquire skills and speed required.

– Skilled hand ‘crafting’ within a production process environment perceived as added value carrying ‘hand made’ branding.

– Multi skilled workers operating in various lower value roles either similar or dissimilar across various production processes within a single plant.

– Workers undertaking low value roles on production lines with limited rotation.

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Findings – ergonomics

“RULA scores across all the observed production line tasks ranged from 3, requiring further investigation to 6/7 (out of 10), (requiring further investigation and changes to be made soon). These scores equated to the majority of tasks presenting low to medium levels of risk”, but with specific cases requiring action.

“Common tasks that were observed in all participating companies werepick, place, inspection and packaging type tasks. Across all companies these engaged similar physical actions”.

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“A large majority of tasks observed as part of this study, resulted in workers adopting poor neck postures (flexed >25 degrees) which were sustained for prolonged periods of time. These tasks were predominantly tasks requiring inspection or placement of product components onto the Lines”.

Findings – ergonomics

“Excessive reaching and twisting was often observed throughout tasks conducted on all participating production lines, these actions were typically conducted frequently at high rates of repetition. Excessive reaching and twisting typically resulted from poor placement of the product on the conveyor in relation to the worker, i.e. outside recommended reach distance. This was often determined by the output mechanism of previous automated process machinery or from trays of additional material being positioned off to the side of the conveyor”. Hence process interaction is a critical aspect.

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“Evidence suggests that work cycle times shorter than 30 seconds, or cycles where more than 50% of the cycle time is involved in the same kind of motion pattern, are strongly related to disorders of the forearm and wrist (Silverstein et al 1986). Cycle times observed on the participating lines ranged from 1.3 to 46 seconds”

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ain“In total 49 production line workers

completed a questionnaire. 25% -30% of workers questioned had some form of ache, pain or discomfort that they attributed to their work activities”

Findings – ergonomics

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• Greater human centred focus to activities in the workplace and interaction with Production machinery and processes.

• More job rotation, and multi skilling to allow flexibility in the plant, and variety of operation.

• Focus on processes and interaction between personnel and machines to reduce reach and stretching, to reduce posture problems, and lifting heavier objects.

• Conveyor and working surfaces at more optimum heights for workers, where safe allow adjustable workstations, and seating.

• Involve employees more in the on going processes associated with workplace Design and improvements.

Conclusions - Ergonomics

Based upon the scope of this assessment ergonomic issues do exist in theWorkplace. Some consideration is given to this, but probably not enough.Means of improving this are :

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·       

i.e Improved ‘job design’ by consideration and analysis in the job definition process alongside the production process.

Methods to achieve this are :

•Evaluation of workload demands•Task simulation•Assessment of Physical actions required and rate of repetition•Analyse recovery actions when system malfunctions•Consider social interaction, personal workspace and worker self esteem•More workforce involvement

•Recognise metrics associated with employee comfort in the workplace more, as part of the business case for change, it is a significant hidden cost in both the short and potentially long term.

CASPERFindings - Automation

“Presentation of the food products for automation needs to be addressed further. Previous experience in other industries suggests that initially this can be done with little/no cost and the better layout in terms of position and orientation improve the efficiency and consistency of the overall handling process…for automation to be successful it is essential that the basic principles of orientation and positioning be developed as core line procedures.”

Vision, alignment and manipulator systems are applied, but need to be ‘more’ appropriate, and priced for the industry.

CASPER• Products can be categorised in to rigid and non rigid forms, e.g

Unpacked ham is non rigid, rigid - bread rolls, or some packed products.

• Automation of rigid products can apply technology transfer using other recognised techniques.

• Non rigid products are more difficult to automate because oflack of databases of experience, and need for newer technologyto handle more complex products and variability.

• The roles identified within CASPER are in many cases relatively simple, and hence may be achieved by automation particularly where skill and value associated is low.

• Cycle times (1-3 sec), position, orientation and accuracy requirements are well within the grasp of automation technology.

• But cost, materials and reliability are critical issues for acceptance

Findings - Automation

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• With many pick and place type roles automation can be appliedas a means of making efficiencies. This is a common theme within the companies assessed, and need not result in overly complex manipulation requirements.

• A cost effective automation/mechatronic approach could have significant benefits

• A system with a target cost of up to £15,000 could open up a new market, for the food and other sectors requiring light weight reliable systems

• The new technology focussing on :– rapid change of function– control by non skilled workers, – ability to rapidly align within the production process

are the key enabling technologies. • Rapid change end effectors to support various functions

Conclusions - Automation

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Outline specification for a suite of modular units.

·     Number of Axes : 4·        Reach : 1m·        Payload : 1 – 2 Kg (including end effector)·        Speed : 1m/s Accuracy : +/- 1mm

System will need to be mobile, and easily located on to set positions on the productionline, where it can align itself with the production process and position of produce.

The system will be designed for hygiene, environment and lubrication requirements that are applicable in the food industry.

Plastics will be used where appropriate to reduce weight and cost, and the design Will Consider minimising the number of mouldings etc.

Programming is a major consideration, and Salford's ‘Virtual teach’ using ‘sensor glove’ techniques are proposed, as a means of enabling Programming and rapid interchangeability of the unit.

CASPERPhased technology development approaches

1. An assessment phase to capture the specification requirements, 2. Simulation work to initiate the design process based upon the 3. motions required against product types.4. Research on the simple programming system for the ‘robot’, 5. functions to be performed

• Selection in the workplace to make the system moveable across functions • Integration with vision systems for location and control purposes,• Man machine interface (ergonomics) and safety

6. Detailed design and development, 7. Works and site trials of prototype hardware.  

Further work is required with potential partners to develop the approachIn to an R&D programme

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Overall conclusion.

• The sector needs to consider ergonomic based metrics alongsidecost metrics within the planning and operations of the production Facility to a greater extent.

• The application of low cost automation against the range of commonpick, place and pack functions needs to be researched further asa potential R&D LINK project, providing affordable solutions.

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Combining the conclusions from the common automation andErgonomic studies generates two potential solutions to improve the

sector :1. Provision of improved company or use of third party

evaluations within process and plant design covering : – Ergonomic evaluation– Simulation of production process and human interaction– Application of ‘lean’ type techniques for layout

2. Technology developments to support low cost automation solutions, ‘plug and play’, multi functional simply controlled units operating within plants covering the high repetition low value tasks.

– An outline specification has been created.

CASPER• For each participating company reports and recommendations

were made on each evaluation to provide a local opportunity for change.

• Each company has been provided with the opportunity of progressing the outcomes within a LINK project to consider low cost automation solutions focussing on :– Lower value jobs

– Common or near common functions

• Creating potential multi company exploitation of common Technology programme.• Considerable potential savings from direct costs of employment, improved efficiency, hidden costs from staff turnover and ergonomic Issues.

CASPERWay forward …..

• As a result of the work undertaken through CASPER - Integrated services for ergonomic and production process improvement are available from INBIS, Loughborough and Salford University. These can be applied to new design or improvement of the production facilities, and reduce ergonomic and safety related problems.

• The opportunity to develop a low cost automation solution remains, and needs to be opened to a wider market in the sector.