<img src="https://secure.office-information-24.com/785669.png" style="display:none;">
Glossary Document Control

SOP

Full name: Standard Operating Procedure
An SOP, or standard operating procedure, is a documented, step-by-step set of instructions describing how to consistently perform a specific process or task. SOPs are controlled documents within a quality management system, meaning they are reviewed, approved, versioned and made available only in their current approved form, ensuring that employees follow the same defined method every time a task is performed. 

Quick facts

Category Documented step-by-step process instructions
Used by Manufacturing, medical devices, pharmaceuticals, aerospace, automotive and other regulated industries
Also called SOP
Related standards ISO 9001, ISO 13485, FDA GMP requirements
Related processes Document control, employee training management, work instructions, change control
Semantic match SOP, standard operating procedure, controlled procedure document, SOP vs work instruction

What is SOP?

An SOP is a controlled document that spells out, in clear, repeatable steps, how a specific task or process should be performed. SOPs cover a wide range of activities, from equipment operation and cleaning procedures to administrative processes like document approval or customer complaint handling.

Because SOPs are controlled documents, they go through the same document control lifecycle as other quality records: drafting, review, approval, distribution and periodic revision, ensuring that only the current, approved version is in active use.

SOPs are sometimes distinguished from work instructions, with SOPs describing a broader process at a higher level and work instructions providing more granular, task-specific detail, though usage of these terms varies across organizations and industries.

Why is SOP important?

SOPs reduce variability by ensuring that a task is performed the same way regardless of who is doing it or when, which is essential for consistent product quality and predictable outcomes.

Well-written SOPs also support training and onboarding, giving new employees a clear, documented reference for how to perform their responsibilities correctly from the start.

In regulated industries, SOPs provide auditable evidence that processes affecting product quality, safety or compliance are defined, controlled and consistently followed, rather than dependent on individual memory or informal practice.

How does SOP work?

A typical SOP lifecycle includes:

  1. Drafting. Document the steps needed to perform the process correctly and consistently.
  2. Review. Route the draft to subject-matter reviewers for feedback.
  3. Approval. Obtain formal sign-off from authorized approvers.
  4. Distribution and training. Make the approved SOP available and train affected employees.
  5. Use. Employees follow the current approved SOP when performing the task.
  6. Revision. Update the SOP as processes change, following the same review and approval cycle.

SOP vs. Work Instruction

Comparison SOP Work Instruction
Level of detail Broader process overview Granular, task-specific steps
Typical scope An entire process, such as equipment cleaning A specific step within that process

Real-world examples of SOP

A pharmaceutical manufacturer maintains an SOP for equipment cleaning between batches, ensuring every operator follows the same validated process regardless of shift or experience level.

A medical device company updates an assembly SOP after a corrective action identifies a step that was previously unclear, retraining affected employees on the revised version before it takes effect.

A food manufacturer references its SOP for allergen changeover procedures during an audit, demonstrating that the documented process was followed consistently across recent production runs.

Regulations and standards related to SOP

ISO 9001 requires organizations to maintain documented information as needed to support the operation of processes, which SOPs fulfill for many operational and administrative activities. ISO 13485 places similar emphasis on documented procedures for medical device manufacturing and quality processes.

FDA GMP requirements for pharmaceuticals and other regulated industries commonly require written SOPs for manufacturing, testing and quality-related activities, with expectations that personnel are trained on and follow the current approved version.

Required by

How QT9 helps with SOP

QT9 QMS SOP and document control capabilities

  • Create, review and approve SOPs through automated document control workflows.
  • Maintain complete revision history for every SOP.
  • Automatically archive obsolete SOP versions to prevent unintended use.
  • Link SOP updates directly to employee training assignments.
  • Provide instant access to the current approved SOP from any location.
  • Support compliance with ISO, FDA and GMP documentation requirements.

Request a Document Control Demo Explore Document Control Software →

See QT9 Software in Action

Discover how QT9 Software helps manufacturers improve efficiency, strengthen compliance and connect quality management and ERP processes within one integrated platform.

Common mistakes with SOP

Common mistakes include writing SOPs that are too vague to ensure consistent execution, or so overly detailed that they become difficult to follow and maintain.

Other problems include failing to retrain employees when an SOP is revised, and allowing outdated printed copies to remain in circulation after a newer approved version has been released.

Frequently asked questions

Usage varies by organization, but SOPs are often used to describe a broader process at a higher level, while work instructions provide more granular, task-specific detail for a particular step within that process.
There is no universal interval. Many organizations set a periodic review cycle, such as annually, while also triggering reviews whenever the underlying process, equipment or requirement changes.
Approval authority typically depends on the process and organization, often involving a subject-matter expert alongside a quality representative, with electronic signatures commonly used to formalize approval.
Yes, typically. When an SOP is revised, employees previously trained on the prior version generally need to be retrained on the new version before continuing to perform the related task.
ISO 9001 requires documented information to support process operation, which SOPs commonly fulfill, though the standard does not use the specific term "SOP" or mandate a fixed document format.
Yes. Many organizations maintain SOPs electronically within a document control system, which supports easier revision tracking, distribution and integration with training records compared to paper-based systems.

Related quality management terms

Related content

Ready to Transform Your Business?

See how QT9 Software helps manufacturers simplify operations, improve traceability and drive continuous improvement with integrated quality management and ERP software.

Last reviewed: July 21, 2026