Processes

Processes

The following definition of processes is adopted from the ANSI/ISA-S88 standard:

A process is a sequence of chemical, physical or biological activities for the conversion, transport or storage of material and energy. Industrial manufacturing processes can generally be classified as continuous, discrete parts manufacturing, or batch. How a process is classified depends on whether the output from the process appears in a continuous flow (continuous), in finite quantities of parts (discrete parts manufacturing), or in finite quantities of material (batches).

Continuous processes

The following definition of continuous processes is adopted from the ANSI/ISA-S88 standard:

In a continuous process, materials are passed in a continuous flow through processing equipment. Once established in a steady operating state, the nature of the process is not dependent on the length of time of operation. Start-ups, transitions and shutdowns do not usually contribute to achieving the desired processing.

Discrete parts manufacturing processes

The following definition of discrete processing is adopted from the ANSI/ISA-S88 standard:

In a discrete parts manufacturing process, products are classified into production lots that are based on common raw materials, production requirements, and production histories. In a discrete parts manufacturing process, a specified quantity of product moves as a unit (group of parts) between workstations, and each part maintains its unique identity.

Batch processes

The following definition of batch processes is adopted from the ANSI/ISA-S88 standard:

The batch processes lead to the production of finite quantities of material (batches) by subjecting quantities of input materials to a defined order of processing actions using one or more pieces of equipment. The product produced by a batch process is called a batch. Batch processes are discontinuous processes. They are neither discrete nor continuous; however they have the characteristics of both.