Introduction for PPCE
- 1. INTRODUCTION
- 2. Manufacturing ■ Although the basis of manufacturing can be traced back as far as 5000- 4000 BC, the word manufacture did not appear until 1567, with manufacturing appearing over 100 years later in 1683. ■ The word was derived from the Latin words manus (meaning 'hand') and facere (meaning 'to make'). ■ In Late Latin, these were combined to form the word manufactus meaning 'made by hand' or 'hand-made'. ■ Indeed, the word factory was derived from the now obsolete word manufactory. In its broadest and most general sense, manufacturing is defined as (DeGarmo et al., 1988)
- 3. However, in more concise terms, it is defined in the Collins English Dictionary (1998) as: ■ Processing or making (a product) from raw materials, especially as a large scale operation using machinery. In a modem context, this definition can be expanded further to: ■ The making of products from raw materials using various processes, equipment, operations and manpower according to a detailed plan.
- 4. ■ It should have worth in the market or a value. Therefore, manufacturing is 'adding value' to the material. ■ The value added to the material through processing must be greater than the cost of processing to allow the organization to make money or a profit. Therefore, added value can be defined as (ICMA, 1974): The increase in market value resulting from an alteration of the form, location or availability of a product, excluding the cost of materials and services. This allows manufacturing to be further defined as: ■ The making of products from raw materials using various processes, equipment, operations and manpower according to a detailed plan that is cost-effective and generates income through sales.
- 5. Manufacturing System A system in which raw materials are processed from one form into another, known as a product, gaining a higher or added value in the process and thus creating wealth in the form of a profit.
- 6. ■ This defines a manufacturing system as (Lucas Engineering and Systems, 1992): An integrated combination of processes, machine systems, people, organizational structures, information flows, control systems and computers whose purpose is to achieve economic product manufacture and inter- nationally competitive performance.
- 7. Inputs and Outputs of a Manufacturing System
- 8. Common Characteristics of a Manufacturing System ■ All systems will have specific business objectives to meet in the most cost-effective manner. ■ All systems consist of an integrated set of sub-systems, usually based on functions, which have to be linked according to the material processing. ■ All systems must have some means of controlling the sub- systems and the overall system. ■ To operate properly, all systems need a flow of information and a decision-making process.
- 10. Developing a manufacturing strategy ■ Six basic decision categories have been identified and these are (Hayes and Wheel right, 1984): ■ Capacity Decisions - these deal with how customer demand is met in terms of the resources available and those required. In effect the questions being asked are, what has to be made, what will be used to make it and when and how will this be achieved? ■ Process Decisions - this is basically about deciding which type of system should be employed. This is complicated by the fact that most companies employ hybrid systems. This decision is linked to four distinct processing strategies
- 12. ■ Facility Decisions - The main focus of this decision is the layout of plant at a factory level, and the assigning of specific products to specific plants at an organizational level. ■ Make or Buy Decisions - The essence of this decision is identifying what is to be made in house and what is to be sub-contracted. This is particularly important as it will influence the capacity, facilities and process decisions. ■ Infrastructure Decisions - This decision considers the policies and organization required to meet the business objectives. Specifically it will consider the production planning and control system, the quality assurance system and the organizational structure. ■ Human Resource Decision - Obviously other decision categories can have a huge influence on this decision. The two main decisions are identifying the functions and organizational structure required and the reward system, that is, pay, bonuses, etc.
- 13. Manufacturing Organizational Structures ■ Sales and Marketing - This part of the organization provides the interface with the market. The main responsibilities of this function are to ensure a steady flow of orders and consolidate and expand the organization's share of the market. Typical sub-functions might include sales forecasting, order pro- cessing, market research, servicing and distribution. ■ Engineering - Typically under this functional heading the sub- functions would include product design, research and development (R&D) and the setting of specifications and standards. The level to which R&D is carried out will depend on the product. For example, in high-tech products, R&D will play a major role in determining the use of materials and processes and future product design.
- 14. Manufacturing - the diversification of the manufacturing function will depend very much on the size of the organization. Typical sub-functions might include: Production planning with responsibility for producing manufacturing plans such as the master production schedule (MPS) and the materials requirements plan (MRP). Quality assurance whose job it is to ensure that products are being made to the required specification. Plant maintenance with the responsibility of ensuring that all equipment and machinery is maintained at an appropriate level for its use.
- 15. Industrial engineering whose responsibilities include the determination of work methods and standards, plant layouts and cost estimates. Manufacturing engineering whose responsibilities includes manufacturing systems development, process development, process evaluation and process planning. Production materials control who coordinate the flow of materials and work through the manufacturing plant (work-in-progress). Stores will usually be included in this function. Production whose responsibility it is to physically make the product.
- 16. ■ Human resources - This is again a broad heading that typically will include sub-functions such as recruitment, training and development, labour relations, job evaluations and wages. ■ Finance and accounts - The main responsibilities of finance include capital financing, budget setting and investment analysis. Accounts generally deal with the keeping of financial records including cost accounting, financial reporting and data processing. ■ Purchasing - This primarily involves the acquisition of materials, equipment and services. They must ensure that the above support the manufacturing capabilities by satisfying their supply need. They must also ensure the quality and quantity of supplies through vendor rating.
- 17. Types of Organizational Structure ■ A functional structure ■ A product structure ■ A matrix structure
- 21. Categories of manufacturing system There are two basic categories of manufacturing system: ■ Discrete parts manufacturing; ■ Continuous process manufacturing. Discrete parts manufacturing involves the manufacture of individual items and can be further classified into: ■ Project manufacture ■ Jobbing shop manufacture ■ Batch manufacture ■ Mass/flow manufacture
- 25. Plant Layout ■ As discussed above, plant layout focuses on the equipment and machinery within the production area and all related areas. ■ However, this requires further definition. Plant layout is about the physical arrangements of departments, workgroups within departments, workstations, machines and stock-holding points within a manufacturing facility. ■ These are also some- times referred to as economic activity centres or work centres.
- 26. The objective is to arrange the people and equipment to operate effectively and allow the smooth flow of work. In general, the inputs to the layout decision are as follows (Chase et al., 1998): ■ Specification of the objectives and criteria used to evaluate the layout design. Typical examples are the required space and the distance travelled between centres. ■ Estimates of product demand on the system. ■ Processing requirements in terms of the number of operations and amount of flow between the elements in the layout. ■ Increasing the efficient utilization of labour and equipment. ■ Reducing hazards to employees. ■ Improving employee morale. ■ Improving communication.
- 27. Types of Plant Layout ■ Process layouts ■ Product layout ■ Fixed position layout ■ Hybrid layouts
- 28. Process layouts
- 29. ■ Resources are general purpose and thus less expensive. ■ It is more flexible as it is less vulnerable to changes in products. ■ Equipment utilization is higher as processes are used across a high variety of products. ■ Employee supervision can be more specialized which is important due to the high skill factor of personnel. ■ Processing rates tend to be slower. ■ Production time is lost due to set-up due to frequent product changeover. ■ High inventory required to keep workstations busy. ■ Lead times tend to be long and variable. ■ Too much material handling. ■ The numerous routings and flows across the shop floor necessitate the use of simple carrying devices such as carts. ■ Production planning and control is more difficult.
- 30. Product layout
- 31. ■ High production rates. ■ Low work-in-progress inventory. ■ Minimizing material handling. ■ Minimizing lost production time due to changeovers. ■ Ease of production planning and control. ■ As the layout is based on the product it is less flexible. ■ Process breakdowns can halt an entire production line. ■ The capacity of the line is determined by the bottleneck work centre. ■ Poor use of resources for low-volume products.
- 33. Hybrid layouts