Overview

The ISA 88 model has become the preferred model for batch production systems. In these systems, a production batch will move through a set of equipment as it is produced, but it follows the rule that there is only one batch in a unit at a time. During the development of the ISA 88 model, there was no attempt to apply it to continuous or discrete manufacturing, but the standard mentions that the models and concepts may be applicable.

While the ISA 88 standard has been successfully applied to many non-batch problems, there has been no consistently defined method for applying it in nonstop production. Nonstop production is a continuous product flow through a facility with no breaks in product flow even when products change. Nonstop production can be either continuous or discrete manufacturing, and is typified by small units that perform actions on part of a batch. Nonstop production may be continuous, such as in the production of chemicals or food, or discrete, such as in the creation and filling of bottles or vials.

Nonstop production is manufacturing where there are no breaks allowed in the product flow. Nonstop production may be required because the physical process does not allow stops or breaks in products, such as in fiber-optic cable production. Alternately, nonstop production may be required when line breaks between production runs, and even different products, are expensive and must be avoided, such as in-filling and packaging operations. Nonstop production occurs in both continuous industries and discrete...