procedure

A procedure is a defined, ordered set of steps that describes how a specific activity is carried out. In industrial and manufacturing environments, it commonly refers to a documented or system-encoded sequence that tells people or automated systems what to do, in what order, and under what conditions.

Core meaning in manufacturing and regulated operations

In regulated and industrial contexts, a procedure typically includes:

• A clear objective or outcome (for example, complete a batch, start up a line, perform an inspection)
• An ordered list of actions or steps
• Roles or resources responsible for each step (operators, units, equipment, systems)
• Inputs and outputs (materials, data, intermediate states)
• Conditions, parameters, or decision points that govern the flow of steps

Procedures may be:

• Document-based, such as written operating procedures, SOPs, or test procedures maintained under document control.
• System-based, such as workflows encoded in MES, batch control, or automation systems.

Procedures in batch and ISA-88 contexts

In batch manufacturing and standards such as ISA-88, a procedure commonly refers to a structured and hierarchical set of actions that defines how a batch is made. It is typically modeled in layers, such as:

• Procedure: the overall sequence for the batch or process segment
• Unit procedure: a subset of steps executed in a specific unit
• Operation: a logical grouping of processing actions
• Phase: the smallest, most detailed step, often linked directly to control logic

In this setting, a procedure is not just a static document but a logical model that can be implemented in control systems, MES, or recipe management tools. It describes the process execution behavior rather than general policies or guidelines.

Operational use

On the shop floor and in supporting systems, procedures show up as:

• Standard operating procedures (SOPs) linked to work centers, products, or recipes
• Electronic work instructions that enforce step-by-step execution and data capture
• Automated sequences in batch, process, or discrete control systems
• Quality, cleaning, changeover, and maintenance workflows

Procedures are often subject to version control, training, and periodic review, especially in regulated industries where traceability and consistent execution must be demonstrated.

What a procedure is not

To avoid confusion, it is useful to distinguish procedures from related concepts:

• It is not the same as a high-level policy or guideline, which describes intent but not detailed steps.
• It is not just a single document describing “how the plant runs”; many specific procedures usually exist for different operations.
• It is not the physical equipment or control hardware, although it may be executed by or on that equipment.

Common confusion

• Procedure vs. process: A process is the broader transformation of inputs to outputs (for example, a production process). A procedure is the defined way in which part or all of that process is carried out, often at a more detailed level.
• Procedure vs. work instruction: Work instructions usually give more granular, operator-facing detail for a specific task (for example, torque settings, tool selection). A procedure may reference one or more work instructions as part of its steps.
• Procedure vs. recipe (ISA-88): In ISA-88 terms, a recipe includes parameters, formulas, and other product-specific information. The procedure is the ordered set of actions within that recipe that defines the execution sequence.

Link back to ISA-88 usage

In ISA-88, the term procedure is used precisely for the ordered set of actions that drives how a batch is produced within the recipe model. This meaning aligns with the general definition: a structured sequence of actions, represented in a hierarchical model and typically implemented in control systems and MES rather than only as a static document.