It is possible to define a system as a meaningful whole that consists of certain parts (sub-units, subsystems), with certain relations between the parts and the relation of the parts with the external environment. Any structure, event or action consisting of unified and integrated parts is treated as a system.
In today's conditions, system approach thinking is widely used in every field. The concept in question also provided a wide viewpoint to production management. While each of the enterprises is considered as a system, the production systems, which are a sub-system of the enterprise, are considered as a framework consisting of activities that can create value for the society.
Production systems; "It is the process of converting the inputs provided from inside and outside the system into a physical output by finding the most suitable component in order for businesses to achieve their determined goals". According to this definition, production systems have three basic elements. These; can be counted as inputs, transformation process and outputs.
Inputs: In order to take part in a production action, there are items called inputs that must be taken from outside to the action center. We can classify the inputs that need to flow into the transformation process in terms of space, time, quantity and quality in two ways. These; uncontrollable inputs and controllable inputs.
- Uncontrollable inputs, although they affect the production system, are those that cannot be affected by the production system. These are other systems that are outside the production system. Legal system, social system, economic system, natural system and psychological system constitute uncontrollable inputs and are named as environmental factors. Although a change in the production system does not make a change in environmental factors, the opposite situation may affect the production system positively or negatively and even make it necessary to redesign.
- Controllable inputs are those whose quantities, forms, locations, qualities, proportions and flows can be changed by the production system. These consist of raw material, capital, worker and technology.
Transformation Process: In terms of production systems, the decision areas of the transformation process, which is a subsystem of the production system, determination of production type, determination of capacity, selection of the place of establishment, scheduling of production, determination of material flow paths, determination of machinery and equipment, layout arrangement, processing and maintenance -Determining the actions related to the repair.
Outputs: The goods and services produced constitute the outputs of the system. When inputs turn into goods and services in the production process, quality and cost information accumulates on the said goods and services. The quantity and characteristics of the quality and cost pair are determined by the stages of the previous production system.
It is seen that the authors, except Gavett and Starr, who named the production types similarly and made a triple classification, generally made a double classification. Authors such as Buffa, Mayer, Boris, and Hopeman used the terms "continuous" and "batch" when classifying production systems, using the criteria for the product's production flow.
In the classification made by Starr and Gavett, each production system class corresponds to one of the traditional settlement types. This classification gains importance as layout planning has an important place in production systems. Starr and Gavett have collected their production systems in three main groups;
- Mass Production (Flow-shop)
- Workshop Type Production (Job-shop)
- Project Type Production (Project-shop)
Although many authors classify serial and workshop type production separately, they consider project type production either within the workshop type production or as a special case of one of these classes.
Apart from the three production types described, the "Cell Type Manufacturing System", which was developed based on the idea of group arrangement and group technology, which came into the agenda especially after the 1970s and emerged as a new production philosophy, will be considered as a separate class.
In addition to the aforementioned production systems, JIT (Just In Time) production method, which originated in Japan and is based on production with zero stock, will be introduced.