Continuous production systems are manufacturing processes where goods are produced constantly and uninterrupted. These systems are characterized by high volume, consistent output, and minimal downtime between production cycles. We will discuss various types of continuous production systems in the next part.
Types of Continuous Production System
The following are the types of continuous production systems:
1) Assembly Lines
2) Continuous Flow
3) Mass Production
1. Assembly Line Production System
An assembly line combines two or more components to produce a finished product. The history of assembly lines may trace back to the USA, where it was introduced and developed in the automobile industry. It is specifically appropriate for the manufacturers engaged in the mass production of a restricted variety of identical products in large batches on an ongoing basis. The assembly line helps strike a proper balance between the technology on one hand and other manufacturing facilities on the other. This ensures the development of a logical approach concerning optimizing the results. It is one of the types of continuous production system.
Characteristics of Assembly Lines
The following features characterize the assembly line method of production:
1) The twin objectives of high rates of output and low unit costs are achievable with the help of special machines and skilled manpower.
2) Restricted flexibility is associated with assembly lines.
3) Consistency maintains as far as the quality level concerns.
2. Continuous Flow
Under the continuous or process production method, processes are closely linked, and production occurs continuously by following a standardized and uniform manner in sequential order. It is one of the types of continuous production system. This technique is appropriate (and popular) in mass processing crude oil into petroleum, diesel, kerosene, etc.
Types of Continuous Flow Production Method
Continuous flow or process production may be of the following two types:
1) Analytical Process
Analytical process proceeds with the breaking down of raw material into various products. For example, analysis of crude oil into gas, petrol, diesel, and kerosene, etc.
2) Synthetic Process
It synthesizes a new product by mixing two or more basic materials. For example, lauric acid, myristic acid, palmitic acid, stearic acid, and linoleic acids synthesize for the manufacture of a new product, viz, soap.
Characteristics of Continuous Flow
The Characteristics of Continuous Flow are as follows:
1) In a secured manufacturing setup, the desired chemical process takes place, and once the chemical reaction is over, the finished products are obtained.
2) Sometimes, useful by-products may also obtain during the intermediate stages of the main process (in addition to the desired end product). For example, turpentine and cold ash are the by-products of paper manufacturing units.
3) Process production being continuous, it is necessary to balance the capacity utilization between various manufacturing stages. This ensures a uniform flow of materials from the raw-material stage, through other stages, to the finished goods stage. The absence of a balancing act may result in gross under-utilization of resources having excess capacity.
4) The level of production (throughout) is in direct proportion to the flow rate of the product.
5) The process industries require heavy capital investment in the initial stage itself; injecting capital incrementally at a later stage is impossible. As a consequence of this, high productivity implies a lower cost of production and vice versa.
3. Mass/Line Production
Mass production may explain as large-scale manufacturing of standardized goods or components. The basic characteristics of mass production are the standardization of materials, machines, products, and processes. The volume of mass production is indirectly proportional to the direct labor cost per unit; the higher the volume of mass production, the lower the direct labor cost per unit. It shows the categorization as types of continuous production system. This process is more appropriate for manufacturing units where production is carried out uninterruptedly, e.g., automobile plants, the electronic industry, the tire industry, the electrical industry, etc. Because of the standardization and mechanization of the processes, the products are generally of high quality.
Characteristics of Mass Production
The following features characterize mass production:
1) In mass production, the same manufacturing setup is used for each product. Each raw material is required to be passed through the same machine in the same sequential order;
2) It involves the processing of just one homogenous product. Production planning, therefore, has to ensure an uninterrupted flow of items to be used as inputs for the production exercise;
3) Mass production does not pose problems relating to the completion of orders for machine capacity or the need for sequencing; the only problem faced relates to the lot sizing’, in case the production unit still needs to be fully deployed. The problem of ‘planning and control’ and coordination between them is also insignificant compared to the one prevailing in single-item manufacturing and batch production.
Advantages of Mass Production
Processing under mass production has the following benefits to its credit:
1) Rate of production is high, whereas the cycle time is low.
2) Capacity utilization is higher because of the time balancing.
3) Operators are not expected to have a high level of expertise; even semi-skilled operators can perform the desired task.
4) Requisite process inventory is low.
5) Production cost per unit tends to be low.
Disadvantages of Mass Production
The technique of mass production suffers from the following shortcomings:
1) Breakdown of a single machine in the sequence results in the total stoppage of the production process.
2) Any change in the product design would necessitate major changes in the line layout.
3) Heavy investment is called for in production facilities.
4) The slowest operation is the determinant of the cycle time.
Measures Taken for Tackling Problems of Line/Mass Production
Flow methods mean that as work on a task at a particular stage is complete, it must be passed directly to the next stage for processing without waiting for the remaining tasks in the “batch.” When it arrives at the next stage, work must start immediately on the next process. For the flow to be smooth, the times that each task requires at each stage must be of equal length, and there should be no movement of the flow production line. In theory, therefore, any fault or error at a particular stage. It is part of the important types of continuous production system. Several requirements must be met so that flow methods can work well.
1) There must be Substantially Constant Demand: If demand is unpredictable or irregular, the flow production line can lead to substantial stock build-up and storage difficulties. Many businesses using flow methods get around this problem by “building for stock”- i.e., keeping the flow line working during quiet periods of demand so that output can be produced efficiently.
2) Product and Production Tasks must be Standardised: Flow methods are inflexible – they cannot deal effectively with variations in the product (although some “variety” can be accomplished through applying different finishes, decorations, etc., at the end of the production line).
3) Materials Used in Production must be to Specification and Delivered on Time: Since the flow production line works continuously, there are better ideas than using materials that vary in style, form, or quality. Similarly, if the required materials are unavailable, the whole production line will come to a close with potentially serious cost consequences.
4) Each operation in the production flow must be carefully defined and recorded in detail.
5) The output from each flow stage must conform to quality standards.
Since the output from each stage moves forward continuously, there is no room for sub-standard output to be “re-worked” (compare this with job or batch production where it is possible to compensate for lack of quality by doing some extra work on the job or the batch before it is completed).
Achieving a successful production flow line requires considerable planning, particularly in ensuring that the correct production materials are delivered on time and that operations in the flow are of equal duration.