SOP:
From Standard Operating Procedure to Verifiably Executed Task

SOP Means Standard Operating Procedure

SOP stands for Standard Operating Procedure, often called Standardarbeitsanweisung or standardisierte Verfahrensanweisung in German. It defines how a recurring activity is to be carried out within a specified scope.

An SOP specifies responsibilities, work steps, checks, records, and how deviations are handled.

In GMP operations, it is part of controlled documentation. EU GMP Chapter 4 expressly distinguishes procedures that prescribe activities from records documenting what actually happened. ^[1]

The SOP is the instruction. The executed task is the activity. The resulting record is the evidence.

An approved SOP does not by itself prove that a particular person carried out the required check for a specific batch. That requires the associated execution record.

SOPs, Procedures, and Work Instructions Serve Different Purposes

These terms overlap in everyday use. There is no universally prescribed document hierarchy. The following distinction can be useful within a quality management system:

The SOP defines the workflow; a digital work instruction provides the instructions at the workstation.

Workflow models can additionally specify when tasks begin, wait for a decision, or trigger a follow-up process.

Organizations may use different labels. What matters is clear instructions and controlled use.

An SOP Needs Clear Steps, Responsibilities, and Records

When creating an SOP, first define the activity it governs and the information needed to perform it.

The following SOP template is an established pattern, not a statutory format.

A good SOP uses clear action verbs. “Check the identification against the goods receipt documents” is an executable instruction. “Observe the identification” does not explain what needs to be checked.

EU GMP Chapter 4, section 4.4 calls for an imperative, mandatory style for SOPs and work instructions. Under section 4.3, instruction documents must be approved, signed, and dated by authorized persons. Their identity and effective date must be clear. ^[1]

Each step should therefore show what to do, which outcome is expected, and what record must be created.

SOP Example: Starting Material RM-427 From Receipt to Release

The following example is fictitious and simplified. It is not a complete sampling instruction.

A pharmaceutical manufacturer receives four containers of starting-material batch RM-427. The approved SOP-WE-12, version 3 applies to handling that delivery.

The starting material remains on hold until Quality Control makes its decision. The timing of sampling, testing, and decision-making can be analyzed through value stream mapping.

EU GMP Chapter 5, section 5.32 addresses the identification of starting materials, including their status. Under section 5.34, only starting materials released by Quality Control within their retest period may be used. ^[2]

The Sample Quantity Is Recorded When the Task Is Performed

The SOP template specifies a sampling target of 50 g.

During sampling, the quantity is recorded and deducted from the inventory of material batch RM-427 in the quarantine area. In this fictitious example, 52 g are sampled and documented.

The instruction and the execution remain distinct: the template sets a target of 50 g; the task records the 52 g actually sampled.

This inventory transaction is a sample withdrawal, not a release of the starting material for production. The remaining material stays in quarantine until the designated decision.

Version, Effective Date, and Training Must Align in GMP Operations

An SOP must be correct in substance. The applicable version must also be the one in effect at the workstation.

EU GMP Chapter 4, sections 4.3–4.5 govern approval, identification, updating, and regular review of documents. ^[1]

Four questions are central:

Which version is approved? A new version becomes an applicable instruction only after the designated approval.

When does it take effect? The effective date must be established.

Who has been trained? EU GMP Chapter 2, sections 2.10–2.11 require task-appropriate training, documentation of training, and evaluation of its effectiveness. ^[3]

What happens to earlier versions? They must not inadvertently guide current work. The document version used for past activities must remain reconstructable.

US CGMP rules also require written, approved production procedures. Under 21 CFR 211.100, those procedures must be followed, activities documented at the time of performance, and deviations recorded and justified. ^[4]

Approval responsibilities of the quality unit are additionally addressed in 21 CFR 211.22. ^[5]

During an inspection, the current SOP on file is not the only concern. Reviewers also need to know which version applied when a past task was carried out.

SOP-WE-12 Becomes a Digital Task Template

The steps of SOP-WE-12 are created in the 420+ SOP and task template library as a reusable template. QA approves and activates version 3; each new task created afterward uses that version. The template is not tied to one delivery. The specific material batch is associated when the task is performed—RM-427 in this example.

The template contains a title, category, description, and ordered steps. The complete SOP can be attached as a PDF and supplemented with images. These remain associated with the relevant version.

In the editor, work steps are defined under “Standard Steps / Checklist”. The section “Data Entry, Checks, and Requirements” contains blocks for documentation and material references.

The following blocks are used in the example:

The editor also supports units, mandatory entries, repeatable checks with minimum entry counts, tables, and notes. In an active task, a repeatable check appears as a measurement record. A live preview shows the entry form used during execution.

The template's planned duration is calculated from the step durations.

Thus the SOP specifies not only what must be done, but also what information must be captured during work.

The SOP Snapshot Preserves the Historical Version

For every executed task, 420+ saves an immutable copy of the step list used—the SOP snapshot.

For sampling RM-427, this is SOP-WE-12, version 3.

Later, QA changes the sampling step and approves version 4. Version 4 becomes active; version 3 becomes inactive.

The task already executed for RM-427 is unaffected. Its snapshot still shows the steps from version 3.

This keeps the instructions that governed the past execution traceable after the change.

Mandatory Steps Remain Open Until Completed or Deferred With a Reason

A task cannot be completed while a mandatory step remains open or a repeatable check has fewer than its required entries—in this example, four containers. If a step cannot be performed at that moment, it is deferred with a reason. The reason becomes part of the record.

This shows which steps were completed, which remain open, and which were deliberately deferred.

The QR Code on the Scale Opens the Relevant Task

Access to the SOP begins at the workstation.

A device QR code is attached to the scale. The worker scans it and opens the task overview associated with that equipment.

The scale is recorded as equipment in the area record, with its category, serial number, and inspection status, such as Calibration due or Inspection passed.

In the task overview, the person finds the fictitious task “Sampling RM-427”.

Opening it displays the steps of SOP-WE-12 V3. The worker does not need to search a folder for the current instruction.

The task can be performed on a tablet, smartphone, terminal, or smart glasses.

With smart glasses and a headset, instructions can be displayed during work and entries prepared hands-free. Both hands remain available for work on the product or equipment.

Voice Input Suggests an Entry—the Person Confirms It

During container inspection, the person says:

“Container 2 of 4, seal intact.”

Voice input transfers this statement as a suggestion into the entry field. The person checks the recognized text and confirms it.

This creates a documented entry for the inspection of the second container.

It does not release the material. Hold or destruction decisions are not triggered directly by voice input either.

Those decisions follow the assigned authority. Role-based process control separates use of the task interface from the authority to take a critical action.

Release of RM-427 therefore remains the responsibility of Quality Control.

A Damaged Seal Triggers a Follow-Up Task

For container 3, the person observes: Seal damaged.

Instead of confirming “acceptable,” the person creates a follow-up action from that step—in this example, “Inspect batch / partial batch” with High priority and a designated person from Quality Control.

The follow-up task inherits the reference to the original task and therefore to material batch RM-427. The observation about container 3 remains in the recorded entry.

Quality Control decides on further use.

Sampling Produces an Execution Record

During execution, 420+ automatically connects documented actions with their process context.

For RM-427, this establishes a traceable connection among step, person, timestamp, value, material, and SOP version.

A simplified excerpt from the fictitious record might look like this:

This entry is a fictitious illustration, not an extract from an actual operation.

Independent Review Has Its Own Statuses

When the template option “Review requires an independent second person” is enabled, the task changes to Pending Review after execution.

The reviewer completes the task or sets its status to Rework Required.

By default, this review applies if the executing person does not hold a reviewer role. The workflow logic is configurable for each organization.

Independent task review is separate from the substantive decision to release the starting material.

Corrections Preserve the Original Entry

A recorded value is corrected rather than overwritten: the original entry stays visible, and the correction can be traced to a person and timestamp.

A task's entries can be exported. The audit trail preserves this history of changes.

The automated compliance evidence is based on information captured during execution. The association is automatic; observations and release decisions remain human actions.

EU GMP Chapter 4, section 4.8 requires records to be made or completed at the time the activity is performed. ^[1]

During batch manufacturing, execution data form part of the documented production history. An Electronic Batch Record links the work steps actually performed and the results to the batch in question.

For RM-427, a later reviewer can ask: Who performed sampling? How much material was withdrawn? What was observed on the containers? What follow-up inspection was triggered? Which SOP version applied?

A Digital SOP Does Not Replace Operational Responsibility

Digital execution depends on the underlying SOP being correct in substance and unambiguous.

An editor cannot fix unclear acceptance criteria or responsibilities. These must be resolved before approval.

The operation also remains responsible for qualifications, training, and regular review of SOPs.

Changes to work steps, checks, or records must be assessed on their merits and approved under control.

For GMP-relevant computerized systems, Annex 11 also requires risk-based validation and controlled changes. Using a computerized system must not reduce product quality, process control, or quality assurance. ^[6]

The benefit of executing an SOP digitally is not simply an electronic form. It is the unambiguous link between the applicable instruction and the work actually performed.