ABSTRACT
Process industries can be divided into two very broad segments: continuous process operation and batch process operations. Batch operations take in very specific quantities of raw materials in an ordered sequence, operate on these in an ordered sequence, and, at the end of processing, produce a batch of finished product. The starting point for the design stage of a control system to automate any batch operation is a complete, written, detailed description of the manufacturing cycle, usually referred to as the process analysis. Control system designers must ensure that the process follows logical steps and is easy to understand, and that the process operators are given complete operating instructions for plant, personnel, and environmental safety. A linear sequence comprises a series of steps that are activated one after the other; in practice, each step is followed by a transition, and each transition by a step.
