Table of Control:-
- Meaning of Production Planning and Control
- Definition of Production Planning and Control
- Objectives of Production Planning and Control
- Scope of Production Planning and Control
- Production Planning and Control in Different Manufacturing System
Meaning of Production Planning and Control
Production planning and control can be regarded as the nervous system of the production operation. This function aims to efficiently utilise material resources, people and facilities in any undertaking through planning, coordination and controlling the production activities that transform the raw material into finished products or components in the most optimal manner. All the manufacturing or production cycle activities must be planned, coordinated, organized and controlled to its objectives.
Production planning and control comprises the planning, routing, project scheduling, dispatching and follow-up function in the productive process, so organized that the movements of material, performance of machines and operations of labour, however, sub-divided, are directed and coordinated as to quantity, quality, time and place. It is adopting as a business principle the adage of plan your work and work your plan. The many systems devised are merely tools or help in accomplishing this purpose. The system which is finally adopted should be as simple and economical as possible and yet be effective in producing the product for delivery when promised, of the proper quality and at the proper cost.
Definition of Production Planning and Control
According to Alford and Beatty, “Production planning and control comprise the planning, routing scheduling. dispatching and follow up function in the productive process, as organized that the movements of material, performance of machines and operations of labour, however subdivided, are direct and coordinated as to quantity, quality time and place. It is adopting as business principle the old saying plan your work and work your plan”.
As per Charles A. Koepke, “Production planning and control may be defined as the co-ordination of a series of functions according to a plan which will, economically utilize the plant facilities and regulate the orderly movement of goods through their entire manufacturing cycle, from the procurement of all materials to the shipping of finished goods at a predetermined rate”.
Objectives of Production Planning and Control
The objectives of production planning and control are below:
1) Better Control: Production planning is the method of control. For better control, planning is a precondition. Only then can one compare performance and calculate deviations, which leads to the power of production.
2) Capacity Utilization: There is a need to use the available resources efficiently and effectively. It is helpful in bringing down various costs of production.
3) Quantity of Inputs: To achieve a level of production, determination of quantity of the inputs and their composition is very important. A product can only be prepared when there is an estimate of the required composition of inputs. If the composition of inputs is not proper, the desired product will not be ready.
4) Timely Delivery: If there is good production planning and control, there will be timely production and the finished product will be rushed to the market in time. This also ensures a better connection with the customers.
5) Nature of the Inputs: To manufacture a product, different types of inputs are used. The quality of the product depends on the nature of the inputs used. Hence the planning is done to determine the nature of various types of inputs which is a complicated process.
6) Ensures Uninterrupted Production: The planning of materials ensures the regular supply of raw materials and other components. The steady flow of materials and supplies is helpful in uninterrupted production.
7) Proper Coordination: It ensures the proper coordination among the workforce, machines and equipment. This leads to the avoidance of wastage and a smooth flow of production.
Scope of Production Planning and Control
The scope of production planning and control can be summarised in the following points:
1) Selecting the best method of processing and finding out the best sequence of operations.
2) To plan the layout of the different operations to be performed.
3) Procurement of raw material, components and spare parts in right quantities at right time from the right source at the right prices.
4) To ensure continuous inspection over products produce.
5) To determine the nature and magnitude of the output in consultation with marketing department.
6) To impose controls over costs and to get work done according to the plan.
7) To prepare and maintain the time schedule.
Production Planning and Control in Different Manufacturing System
Following are the PPC in different manufacturing system:
- PPC in Mass and Flow Production System
- PPC in Batch or Intermittent Production
- PPC in Job Order Production
1. PPC in Mass and Flow Production System
Continuous production is the specialized manufacture of identical articles on which the equipment is fully engaged. Continuous production is normally associated with large quantities and high rate of demand. Since identical articles are produced the operations are repetitive, production auxiliary aids, such as special tools, jigs and fixtures material handling system, inspection devices can be used advantageously.
Continuous production can be categorised into two types:
- Mass production
- Flow production
i)Mass Production
In mass production, a large number of identical articles are produced, but inspite of advanced mechanization and tooling the equipment need not he specially designed for this type of article only. Both plant and equipment are flexible enough to produce other products involving same production processes
If the management decides that a certain line should be discontinued, the machinery can he switched over to produce another article. Such change in policy usually does not involve major modifications in plant layout but change in tooling may be quite possible.
A shop of automatics is an example associated with mass production. Although, the automatics may be continuously engaged on the production of, say a certain type of opinions, they can be switched over to production of screw or similar machine elements when the tieed arises. Another example is a highly mechanized press shop that can produce different components or products made of sheet metal without introducing significant changes in the shop layout.
ii) Flow Production
In flow production, the plant, its equipments, and layout are primarily designed to manufacture the product in question. Flexibility in selection of products for manufacture is confined to minor modification in layout or design of models. Notable examples are automobiles, engines, household machinery, chemical plants etc A decision to switch over to a different kind of product may not only result in extensive tooling (this is often needed even when only the model is changed) but also in basic changes in layout and equipment policy especially when special purpose machines and complex material handling systems are involved. Production planning and control in continuous production is usually far simpler than in job or batch production. Extensive effort is required for detailed planning before production starts, but both scheduling and control need not usually be very elaborate.
2. PPC in Batch or Intermittent Production
Batch production is the manufacture of a number of identical articles either to meet a specific onder or to satisfy the continuous demand. The decisions regarding tooling, jigs, and fixtures depend on the quantities involved in the production batch.
In batch production, there can be three types, namely:
1) A batch produced only once,
2) A batch produced periodically at known intervals, to fulfil continuous demand.
3) A batch is produced constantly at irregular intervals when the necessity arises.
Here again, planning and control are simplified as quantities increase and manufacturing becomes more regular. Two problems that may arise in batch production are related to the batch size and production scheduling.
The answer to these problems generally depends on whether the production is governed by the following:
1) External customer orders only.
2) Whether the plant produces for internal consumption, i.e., a sub-assembly used in the final product.
In the case of external customer orders, the customer order size usually determines the batch size. The timing will also depend on the delivery dates set by the customers. For internal consumption, both batch size and production scheduling problems are decisions made by internal management. The problem of the optimal batch size has to consider the set-up costs involved before each production run and the inventory carrying costs incurred when the finished product is held in stock. The batch size determines the length of the production run and affects both the production schedule and batch size considerations for other products.
3. PPC in Job Order Production
Job production involves manufacturing products to meet specific customer requirements or special orders. The quantity involved is usually tiny. Job production includes manufacturing large turbo generators, boilers, steam engines, processing equipment, material handling equipment, shipbuilding, etc. Under job production, we may have three types, depending on the regularity of manufacture, namely:
1) A small number of products are produced intermittently when the need arises.
2) A small number of products are produced periodically at known intervals of time.
3) A small number of products produced only once.
When the order is to be executed only once, there is potential for improving production techniques by introducing intricate method studies, special tools, or jigs and fixtures unless the technical requirements justify them. However, if the order is repeated, jigs, fixtures, tools, and specially designed inspection gauges should be carefully considered to reduce manufacturing lead time.
PPC function is relatively challenging in job production due to the following given reasons:
1) Specific job orders are assigned to different workstations based on capacity availability.
2) Every job order is different and has a unique sequence of operations. There is no standardized routing for job rankings.
3) Scheduling depends on assessing production time, and estimating is based on judgment.
4) Production schedules are drawn based on the relative priority assigned to different job orders.