UMDA standards notes
ISA-88 is the standard for batch control. Its gift to the industry is separation: the recipe that describes how to make a product is kept apart from the equipment that makes it, so the same plant can make many products and the same product can move between plants. In the UMDA's division of labor, ISA-88 answers the why, the how, and the when of production; its companion ISA-95 answers the where, the who, and the what. These notes define its objects the way practitioners use them. For the normative text, buy the standard from ISA. For the framework that puts these objects to work, see the Unified Manufacturing Data Architecture.
Each object below has a stable anchor. Tools in the UMDA toolset link here from their exports, for example an RDF ontology whose Batch class points at its ISA lineage via rdfs:seeAlso. If a link brought you to this page, the highlighted heading is the object your model descends from.
ISA-88 in one picture: three models side by side. The process model says why (what the product needs, no equipment named), procedural control says how and when (the recipe's elements in running order), and the physical model says which equipment does it. A batch is what happens when a control recipe runs on real equipment; a campaign is a run of batches back to back. Solid arrows are containment; dashed lines pair a level with its counterpart one frame over. The operation keeps no equipment pairing on purpose: it completes inside whatever unit its unit procedure claimed. Select any box to jump to its definition.
isa88:BatchOne production run of a product through a recipe. The word does double duty on purpose: the material being made, and the record of making it. When quality asks what happened to batch 4711, they mean both at once.
The batch is the natural center of gravity for genealogy, deviations, and release. Most pharma data models that work are batch shaped.
isa88:CampaignA series of batches made back to back from the same master recipe: run this product for two weeks, then change over. Campaigns are how batch plants think about utilization, and the level where scheduling trades cleaning and changeover time against demand.
isa88:RecipeThe definition of how to make a product. ISA-88 layers it: a general recipe that knows no site, a site recipe adapted to local materials and language, a master recipe adapted to a process cell, and a control recipe for one specific batch. Each layer trades portability for executability. A recipe carries a formula (the quantities and setpoints), its equipment requirements, and a procedure; the procedure is what actually runs.
isa88:RecipeProcedureThe strategy part of a recipe: the ordered set of unit procedures that makes the product. The procedure is deliberately equipment independent. Binding it to real units happens late, which is the whole trick that lets one recipe run on many trains.
isa88:UnitProcedureA contiguous stretch of the procedure carried out in one unit: everything that happens in the reactor before the material moves on. One unit works on one batch at a time, so unit procedures are also the level where campaigns queue and schedules collide.
isa88:OperationA major processing sequence within a unit procedure: charge and mix, react, cool. Operations usually carry the process intent, and they are commonly the level at which batch records group their steps. An operation runs to completion in the same unit it started in.
isa88:PhaseThe smallest element of procedural control: one discrete action against the equipment. Charge 100 kilograms. Heat to 60 degrees. Hold 30 minutes. Phases are where recipe meets equipment: the recipe asks for a phase, the equipment offers one, and the handshake between them is the most tested interface in a batch plant.
isa88:ProcessWhat the product needs to happen, described without naming any equipment: the chemistry and physics of making it. The process model is the why behind every recipe. Procedures exist to make a process happen in a real plant.
isa88:ProcessStageA major part of a process that results in a planned sequence of chemical or physical changes: reaction, crystallization, drying. Stages are how process engineers talk about a product before anyone asks which tank it will use.
isa88:ProcessOperationA major processing activity within a stage: charge, heat, hold. Where the procedural operation says how equipment will do the work, the process operation says what must happen to the product.
isa88:ProcessActionThe smallest described piece of processing: add material X, raise the temperature to Y. Process actions are the equipment-independent twins of phases, and comparing the two is a quick audit of whether a recipe still matches its process.
isa88:ProcessCellThe set of units and supporting equipment a batch needs from start to finish: the granulation suite, the brewhouse, the API train. A process cell can hold more than one path through it, and choosing the path for a given batch is what scheduling a batch plant actually means.
isa88:UnitA major piece of processing equipment that hosts one batch at a time: a blender, a reactor, a coater. Units own their auxiliary equipment and expose their capabilities as phases. In the ISA-95 equipment hierarchy the unit sits as a level; ISA-88 tells you what it does all day.
isa88:EquipmentModuleA functional group of equipment inside a unit that carries out a minor processing task: a dosing header, an agitator with its drive, a jacket temperature group. Equipment modules bundle the control modules they need, and a well-chosen set of them is what makes a unit's phases clean to write.
isa88:ControlModuleThe smallest grouping of equipment that can carry out basic control: a valve with its limit switches, a pump with its starter, a transmitter with its loop. Control modules are the bricks everything above them is built from, and the place where the batch world finally touches an actual output.
Companion page: ISA-95 objects in plain language. See how these objects translate to OPC UA, MQTT/Sparkplug B, B2MML and more in the Standards Crosswalk, or model them and export schemas with the Common Data Model Designer.
Part of the UMDA standards notes and the UMDA toolset. ISA-88 is a standard of the International Society of Automation; these plain language notes are not a substitute for the normative text. The Unified Manufacturing Data Architecture is described at umda.info. Notes © 2026 Unified Manufacturing Data Architecture. All rights reserved.