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Unit Procedures

Unit Procedures page

A unit procedure is a subset of a batch procedure that runs on a single equipment unit (work center). It groups operations into an ordered sequence that represents everything happening at one piece of equipment during a batch.

Unit procedures sit at the second level of the ISA-88 procedure hierarchy:

Example: A "Mixing Process" unit procedure groups all operations that take place at the mixing tank, from ingredient preparation through heating, mixing, and holding.

Page layout​

The Unit Procedures page (Admin > Procedures > Unit Procedures) displays:

  • Dashboard cards: total, active, and inactive unit procedure counts
  • Filter bar: search, inactive toggle, column visibility controls
  • Data grid: all unit procedures with their operation counts and inline actions

Unit procedure fields​

FieldRequiredDescription
NameYesDisplay name (max 255 characters)
CodeYesUnique short identifier (max 50 characters), e.g., MIX_PROC, PAST_PROC
DescriptionNoLonger explanation (max 1000 characters)
Equipment ClassNoThe equipment class required to execute this unit procedure. When set, the system can validate that a production order assigns compatible equipment.
ActiveYesWhether the unit procedure is available for use

:::info Equipment classes vs. specific equipment The Equipment Class field specifies a type of equipment (e.g., "Mixing Tank"), not a specific machine. This keeps procedures generic. The actual equipment assignment happens at the production order level, where a specific mixing tank is selected from the available units of that class. :::

Creating a Unit Procedure​

  1. Click Add Unit Procedure above the data grid
  2. Enter the Name and Code (both required)
  3. Optionally select an Equipment Class and add a description
  4. Click Create

Create unit procedure dialog

Managing operations within a unit procedure​

Click the list icon on a unit procedure row to open the Manage Operations dialog.

Manage operations dialog

Adding an Operation​

  1. Select an operation from the dropdown (only active operations not already linked are shown)
  2. Click Add

The operation is appended at the end of the sequence.

Reordering operations​

Use the up arrow and down arrow buttons to change execution order. The sequence number determines which operation runs first, second, and so on.

Removing an Operation​

Click the red trash icon to unlink an operation. This does not delete the operation itself.

:::tip Same operation, different contexts An operation can be linked to multiple unit procedures. For example, a "Clean In Place" operation might appear in both a "Mixing Process" and a "Filling Process" unit procedure, each with its own sequence position. :::

Editing a Unit Procedure​

Click the edit button (blue pencil icon) to modify name, code, description, equipment class, or active status.

Deleting a Unit Procedure​

Click the delete button (red trash icon). Deletion will fail if the unit procedure is still linked to any batch procedures.

Grid Columns​

ColumnDescription
NameUnit procedure display name (bold text)
CodeUnique code shown as a chip
DescriptionOptional description text
Equipment ClassRequired equipment class name, or -- if none
OperationsCount of linked operations (chip)
StatusActive/Inactive chip
ActionsManage Operations, Edit, Delete buttons

The Created At and Updated At columns are available in full-column mode.

Operation Sequence Example​

Here is the "Mixing Process" unit procedure with its operation sequence:

#OperationCodePhases
1Prepare IngredientsPREP_INGRDose Ingredient, Agitate
2Heat and MixHEAT_MIXSet Temperature, Agitate, Hold

The operations execute in order: first prepare ingredients, then heat and mix. Each operation in turn executes its own phases in sequence.

Best Practices​

  1. One equipment unit per unit procedure: this is a core ISA-88 principle. If your process uses two different tanks, create two separate unit procedures, even if the steps are similar.
  2. Set equipment classes: linking to an equipment class enables validation at the production order level and helps with scheduling.
  3. Name by equipment and process: use names like "Mixing Process" or "Pasteurizer CIP" that make it clear both where and what.
  4. Consider the execution flow: arrange operations in the order they actually execute. Parallel operations within a unit procedure are not supported (parallelism is handled at the batch procedure level between different unit procedures).
  • Operations — the building blocks that unit procedures compose
  • Batch Procedures — the next level up, composing unit procedures with parallel execution support
  • Equipment — configure equipment classes that unit procedures reference
  • Batch Model (ISA-88) — the complete hierarchy explained

Prerequisites​

Next steps​