SOP Lifecycle — Writing, Approving, and Retiring Controlled Documents¶

Read before: what-is-gmp-documentation (documents vs records), alcoa-plus-principles (ALCOA+).

What it is¶

A Standard Operating Procedure (SOP) is a controlled, written instruction for a specific, repeatable task. "Controlled" means the document is part of a managed system: it has a unique number, a version, an owner, and a defined path from creation to retirement.

The SOP lifecycle is the journey every SOP travels:

Draft → Review → Approve → Issue & Train → Active Use
  ↑                                              |
  |____________ Change Control __________________|
                                                 |
                                             Retire / Supersede

The same lifecycle applies to all controlled documents — product specifications, master formulas, labels, cleaning procedures. SOPs are used here as the primary example because they are the most common document type in a GMP operation.

Why it matters¶

An SOP has two jobs simultaneously: it standardises the task (everyone does it the same way, every time) and it proves the task was done correctly (the corresponding record shows the SOP was followed).

Neither job works if the document system is chaotic. When regulators find multiple versions of the same SOP circulating, or staff working from an SOP that has not been updated in four years, or training records that post-date the effective date of the procedure, they draw two conclusions:

Your operation may not be under control.
Your records cannot be trusted, because you cannot demonstrate that the people who created them were working from the correct, approved version of the procedure.

A functioning SOP system is also self-protective: when something goes wrong, an auditor's first question is "what does the SOP say?" If your SOP was correct and your records show it was followed, you have a starting point for investigation. If there is no SOP, or it was never updated, you have no defence.

What you must do¶

Step 1 — Set up a document numbering system¶

Before writing your first SOP, establish the system that will number and track all your documents. Consistency from the start prevents the chaos of retroactively numbering a growing collection.

Recommended format: SOP-[CODE]-[NNN]

Field	Meaning	Example
`SOP`	Document type (fixed)	`SOP`
`[CODE]`	Section code from the taxonomy	`PROD`, `EQ`, `QMS`
`[NNN]`	Sequential three-digit number within that section	`001`, `002`

Examples: SOP-PROD-001 (first production SOP), SOP-EQ-003 (third equipment SOP), SOP-QMS-001 (quality policy).

Version numbering:

Version change	When to use	Example
Major (X.0)	The procedure itself changes	V1.0 → V2.0
Minor (X.1)	Typographical corrections, formatting — no change to the procedure	V1.0 → V1.1

Whether a change is major or minor must be decided by QA, not by the author. Err on the side of treating it as major — a new version is a small administrative burden; an undetected procedural change recorded under an old version number is a compliance finding.

Create a Document Master List (also called a Document Register) — a simple spreadsheet or table listing every controlled document: its number, title, current version, owner, effective date, and next review date. This becomes your single source of truth for what documents exist and which version is current.

Step 2 — Draft the SOP¶

The author should be the person who knows the task best — typically the person who performs it, with input from their supervisor. First drafts do not need to be perfect; they need to be accurate and reviewable.

Content rules for a well-written SOP:

One procedure per SOP. Do not combine unrelated tasks in one document; it makes revision harder and training harder.
Numbered steps, not paragraphs. Each step is one action: "Switch on the balance and allow 10 minutes to warm up." Not: "The operator should ensure the balance has been switched on and warmed up before use."
Specific, not general. "Weigh 500 g ± 5 g" is a step. "Weigh an appropriate amount" is not.
Written for the user, not the auditor. An experienced operator should be able to follow it without asking for clarification. An unfamiliar operator should be able to perform the task correctly from the SOP alone.
Include safety and quality critical points. Flag steps where an error would cause a safety risk or a product quality failure. Mark these visibly (e.g., bold text, a warning symbol, or a "Critical step" label).

Use the standard SOP template (_templates/template-document) which includes the mandatory header fields: document number, version, effective date, author, reviewer, and approver.

Step 3 — Review the draft¶

The draft must be reviewed before approval. For a small operation, two reviews are sufficient:

Technical review — a person with expertise in the procedure confirms the steps are correct, safe, and practically achievable. This is often a senior operator or production manager.
Quality review — the QA responsible person confirms the document meets GDocP requirements: correct format, appropriate level of detail, consistent with related documents.

The reviewer signs and dates the document. Comments are resolved by the author. Significant changes restart the review.

Do not skip this step because you are the only person in the operation. Have a colleague, a consultant, or a contract QA reviewer perform the quality review. An author reviewing their own SOP misses errors that a fresh pair of eyes catches.

Step 4 — Approve the document¶

Only an authorised person may approve a GMP document. In most small operations this is the Quality Assurance responsible person (QA lead, or the founder if they hold the quality role). The approval signature means:

The procedure is technically correct.
It meets the required GDocP standards.
It is authorised for use from the effective date.

Record the effective date on the document — the date from which the SOP is active. This is not always the same as the approval date: you may approve an SOP two weeks before the equipment it covers is installed. The effective date marks when staff are expected to follow it.

Step 5 — Issue and distribute¶

Once approved, the SOP must reach the people who need to use it before the effective date. Decide how you will manage distribution:

Paper-based distribution: - Print the master copy and file it in the QA master binder. - Print controlled copies for use in each relevant area (production, QC lab, etc.). - Mark each copy with its location: "Controlled Copy — Production Binder 1." - When a new version is issued, retrieve or destroy the old copies from all locations.

Digital distribution: - Maintain one authoritative folder (e.g., a shared drive with access controls). - Only the current version is in the active folder; superseded versions are archived. - If printing is needed for use on the production floor, stamp printouts: "UNCONTROLLED COPY — valid on date of printing only. Check master for current version."

Keep a distribution record for each SOP: who holds a controlled copy and when they received it. This enables you to recall all copies when a revision is issued.

Step 6 — Train before the effective date¶

No one should follow an SOP they have not been trained on. Training must happen before the effective date, not after. The sequence:

Issue the approved SOP.
Conduct training: the trainer walks through the SOP with the trainees, explaining each step and demonstrating where relevant.
Verify understanding: trainees sign the training record, confirming they have read, understood, and are competent to follow the SOP.
Effective date arrives: trained staff begin using the procedure.

The training record must link to the specific SOP number and version. "Trained on general hygiene" is not sufficient. "Trained on SOP-PERS-001 V1.0 on 2026-04-10, signed by trainee and trainer" is.

Step 7 — Manage changes through change control¶

An SOP must never be informally edited. If a procedure changes — even slightly — the change must go through a controlled process:

Identify the need for change (e.g., a new piece of equipment, a process improvement, a regulatory update).
Raise a Change Request — a brief document stating what needs to change, why, and the proposed new text.
Assess the impact: does the change affect product quality? Product safety? Other SOPs that reference this one? Staff training?
Draft the new version, review, and approve it as per Steps 2–4.
Issue the new version and retire the old (Step 8).

Change control prevents ad-hoc edits that are undocumented and untrained. Even if the change is an improvement, an untrained staff member following an old copy of a changed SOP is a compliance failure.

Step 8 — Periodic review¶

Every controlled document must be reviewed on a schedule to confirm it is still current, correct, and fit for purpose. Set the next review date at the time of approval — typically every one to two years for most SOPs.

At each review: - Is the procedure still how the task is actually performed? - Have any materials, equipment, or regulations changed? - Have any near-misses or non-conformances revealed a weakness in the procedure?

If the SOP is still correct: extend the review date and re-approve with the date and a brief note ("Reviewed — no changes required").

If changes are needed: initiate change control (Step 7).

A Document Master List with next review dates, reviewed monthly, prevents SOPs from going years without a check.

Step 9 — Retire superseded versions¶

When a new version is issued, the previous version is superseded. Superseded documents must be:

Removed from all active use locations. Collect controlled copies from every area. For digital systems, move the old version to an archive folder.
Marked as obsolete. Stamp paper copies "SUPERSEDED — Do not use" and include the date. Archive rather than destroy — you will need the old version if an auditor asks what procedure was in use during a batch that was made last year.
Recorded in the Document Master List. Update the version and effective date.

A superseded SOP left in a production binder is a common finding and a direct risk: if a staff member uses the old version, any batch made under it may be non-compliant.

What "good" looks like¶

Trace SOP-PROD-001 through one complete revision cycle.

Background: SOP-PROD-001 V1.0, Mixing Procedure for Lotion Base, was approved on 2026-01-10 with an effective date of 2026-01-20. After six months of use, a process validation study shows that a mixing time of 25 minutes (currently specified) achieves better homogeneity than the original 20 minutes. A revision is needed.

Stage	Event	Document/record created
Change initiation	Production manager raises Change Request CR-2026-008: "Increase mixing time from 20 to 25 min following PV study PVR-2026-003."	Change Request CR-2026-008
Drafting	Author edits Step 7 of SOP-PROD-001. All other steps unchanged. QA confirms this is a major change (procedure affected). Version becomes V2.0.	Draft SOP-PROD-001 V2.0
Technical review	Production manager reviews and signs: procedure is correct and achievable.	Signed review page on draft
QA review	QA lead reviews format and GDocP compliance, signs.	Signed review page on draft
Approval	QA lead approves V2.0. Effective date set: 2026-08-01 (two weeks away for training).	Approved SOP-PROD-001 V2.0, effective 2026-08-01
Training	All production operators trained on V2.0 on 2026-07-25. Training record TR-2026-047 signed by each trainee and trainer.	Training Record TR-2026-047
Issue	V2.0 placed in production binder. V1.0 removed, stamped "SUPERSEDED 2026-08-01", archived in QA binder.	Distribution record updated
Document Master List	Updated: SOP-PROD-001 now shows V2.0, effective 2026-08-01, next review 2027-08-01.	Document Master List

Any batch manufactured on or after 2026-08-01 must follow V2.0. Any batch manufactured before that date was correctly governed by V1.0 — both versions are archived and retrievable.

Common mistakes¶

No version numbering. Using dates as versions ("SOP-PROD-001 May 2026") creates confusion when two versions exist in the same month. Sequential numbers with major/minor distinction are unambiguous.
Obsolete copies left in production. The single most common document control finding. Establish a retrieval protocol at the point of issuing every new version — do not assume people will return old copies unprompted.
Training after the effective date. If an operator follows an SOP before being trained on it, the activity is non-compliant regardless of whether it was done correctly. Training must precede use.
Procedures that describe how things used to be done. An SOP that was written three years ago and never reviewed often describes a process that has since drifted. The staff follow the actual practice; the SOP describes something different. Auditors spot this quickly by asking operators to walk through the SOP step by step.
SOPs so long that nobody reads them. An SOP covering five unrelated procedures in 30 pages will not be read carefully and will not be kept current. Narrow scope and short length are features, not limitations.
Author is also the sole reviewer and approver. In a very small team this is sometimes unavoidable, but it should be documented as a known risk and mitigated (e.g., an external QA consultant performs the quality review). Never have one person draft, review, and approve without any independent check.

Templates & checklists¶

_templates/template-document — The standard SOP/document template with all required header fields.
[[document-master-list]] — [to be created] — Spreadsheet template for tracking all controlled documents, their current version, owner, and next review date.
[[sop-review-checklist]] — [to be created] — Checklist for the QA reviewer to confirm a draft SOP meets GDocP requirements before approval.