Production Planning & Control

An Introduction

The Concept

• Planning: consideration of all input variables to achieve predetermined output goals; a pre-production activity to determine optimal production schedule, operation sequence, economic batch quantity, etc.

• Control: remedial action to prevent variance of output from planned levels; tracking operations to ensure compliance with planned levels

Production Planning Stages

• Defining objectives• Setting priorities to attain objectives• Examining internal & external environments

of planned system• Determining achievable targets• Determining inputs needed to achieve targets

Objectives

• Effectiveness: goods to fulfill customers’ needs

• Maximising output: maximum output with minimum input

• Quality control: Product/service quality meets planned quality specifications

• Minimise throughput time: conversion of RM to FG in minimum time

Objectives (continued)

• Capacity: full utilisation of men & machines• Minimise cost: minimum cost of production • Maintaining inventory: optimal inventory• Flexibility: flexibility in production operations• Coordination: between men & machines

Objectives (continued)

• Capacity: plan for current & future needs • Reduce bottlenecks: solve production

problems early• Maximise profit: minimise cost• Production schedules: as per plan• Routes & schedules: to optimise use of men,

material & machinery• Maintain performance: maintain standards

Functions of Production Planning• Product selection & design• Process selection & planning• Facility location• Facility layout & materials handling• Capacity planning• Systems & procedures• Estimating quantity/costs of production, men• Routing operation sequence• Job scheduling & loading

Functions of Production Control

• Inventory control: MRP; JIT• Time management• Quality control• Maintenance & Replacement• Cost reduction & cost control• Dispatch• Expediting/Follow-up/Progressing

Scope of Production Planning & Control

• Material: RM, components, spares; right quantity; right time

• Methods• Machines & equipments• Manpower• Routing• Estimating• Loading & sceduling

Scope of Production Planning & Control (continued)

• Dispatching• Expediting• Inspection• Evaluating• Cost control

Phases in Production Planning & Control System

• Planning: Pre-planning – product planning & development; demand forecasting; resource planning; facilities planning; plant location & layout

Active planning – quantity planning; product mix; routing; scheduling; material planning; process planning; capacity planning; tool planning

Phases (continued)

• Action phase: execution – dispatching; progress function

• Control phase; status reporting; material control; tool control; inventory control; quality control; labour output control; cost control

Benefits of Production Planning & Control

• Higher quality• Better resource utilization• Reduced inventory• Reduced manufacturing cycle time• Faster delivery• Better customer services• Lower production costs

Benefits (continued)• Lower capital investment• Higher customer service• Improved sales turnover• Improved market share• Improved profitability• Competitive advantage• Flexibility• Dependability• Lower prices

Limitations of Production Planning & Control

• Based on assumptions• Resistance to change• Time consuming• Difficult due to rapid environment changes

Measuring Effectiveness of Production Planning & Control

• Delivery• Inventory levels• Production/Operations Management

Requirements for Effective Production Planning & Control

• Sound organisational structure• Delegation of authority• Reliable, up-to-date feedback • Standardisation• Trained people• Flexibility to adapt • Appropriate management policies• Accurate assessment of

manufacturing/procurement lead times• Adequate plant capacity

Techniques

• Planning & Control of Reserves; deterministic/non-deterministic systems

• Network analysis: PERT – Project Evaluation & Review Technique CPM – Critical Path Method• Reliability Theory: probability Series structure – 1 2 Parallel structure – 1 2

Planning & Control in Different Production Systems

• Job Production: Difficult – no standardised routing of job orders Orders assigned to workstations as available Scheduled on relative priority of job order Scheduled on assessed production times;

estimates of judgement

Different Production Systems (continued)

• Batch: Produced once Repeated at irregular intervals as needed Produced periodically at known intervals• Solution depends on: External customers orders Internal consumption – sub-assembly