Buying Decisions for ISA-88 Batching SolutionsDEFINITIONS PAC:  Programmable Automation ControllerPhase:  The lowest level of procedural element in the procedural control model.  It provides an interface to basic control.Physical Model:  A representation within the ISA-88 product of the physical assets that comprise the batching system.Procedural Model:  A representation within the ISA-88 product that describes a set of activities to beperformed by the Physical model to produce a product or type of product.Unit:  A collection of associated control modules and/or equipment modules that can carry out one or more major processing activities. INTRODUCTION This paper intends to address the decision making around formal ISA-88 batching products such as Rockwell Automation’s FactoryTalk® Batch. Going forward we will simply use “products” as the expression for formal products that embrace the full ISA-88 standard. There are elements of the ISA-88 standard that have migrated into well- structured applications that don’t use a formal product. Such structure can prove to be helpful and has even gained acceptance outside of the batching industry. This paper, however, intends to help guide the thought process through the evaluation of whether or not you actually need and would benefit from such formal products– and in many …