Standard Operating Procedure (SOP)

A Standard Operating Procedure (SOP) is the detailed, step-by-step documentation established by a manufacturer to define and control the manner of production and quality system processes. SOPs are crucial for ensuring consistency in process execution, reducing variation, and maintaining compliance, regardless of who performs the task.

A Standard Operating Procedure (SOP) is a detailed, formal set of written instructions within a quality management system (QMS) that defines the exact steps for performing critical processes consistently and accurately.

SOPs are a fundamental type of required documentation in highly regulated industries, especially medical device manufacturing (governed by FDA 21 CFR Part 820) and Good Manufacturing Practice (GMP) requirements.

Mandate and Purpose of SOPs

SOPs are specifically required to control processes and ensure conformity to standards and specifications:

Production Control

Manufacturers are required to develop, conduct, control, and monitor production processes to ensure a device conforms to its specifications. Where necessary, this control includes documented instructions, standard operating procedures (SOPs), and methods that define and control production.

Consistency and Quality

SOPs are the backbone of a consistent and effective QMS. They ensure that critical processes are performed consistently, reducing variability and eliminating inconsistency.

GMP Compliance

For medical device manufacturers subject to the Quality System Regulation (QSR), the requirement to establish quality system procedures and instructions is mandatory. The new Quality Management System Regulation (QMSR), effective February 2, 2026, requires FDA to revise or develop relevant documents, including Standard Operating Procedures.

Specific Regulatory Applications

The FDA requires manufacturers of tracked devices to establish a written standard operating procedure for the collection, maintenance, and auditing of data related to those devices, and this SOP must be made available to the FDA upon request.

Hierarchy and Structure within the QMS

SOPs fit into the traditional hierarchy of QMS documentation, bridging high-level policies with specific records:

• Relationship to Procedures: Work instructions (which are closely related to SOPs) can be part of a procedure or referenced from it.
• Level of Detail: Standard Operating Procedures (SOPs) are detailed, step-by-step instructions that ensure consistency. They focus on the sequencing of steps, the tools and methods to be used, and the required accuracy.
• Document Hierarchy: In the traditional approach to QMS documentation, the hierarchy flows from the broad (Quality Policy and Quality Manual) down to the detailed instructions and evidence: Quality Policy → Quality Manual → Procedures → Work Instructions/SOPs → Records and Forms.

Documentation Requirements and Training

The process of creating and maintaining SOPs is subject to rigorous controls:

Documentation Control

SOPs, as documents required by the QMS, must be controlled. This involves designated individuals reviewing and approving them prior to issuance, ensuring the documents are available where needed, and promptly removing obsolete versions. Changes to SOPs must be reviewed and approved, and records of the change (including a description, affected documents, signature, and effective date) must be maintained.

Involving Personnel

When developing SOPs, it is crucial to involve the people who actually perform the work, as their insights are invaluable for creating procedures that are both practical and effective.

Training

A QMS is only effective if the people implementing it are trained. SOPs form a key part of the documentation used for training personnel to ensure they are qualified to perform the operations.

SOPs in Contexts Beyond Production

SOPs are required across various functions, not just on the manufacturing floor:

Manufacturing and Production: SOPs describe the processes to be performed and measured, the use of suitable equipment, the monitoring of critical parameters, and contamination control.

MDR Procedures: For medical device reporting (MDR), user facilities, importers, or manufacturers must develop, maintain, and implement written MDR procedures (SOPs) for internal systems to identify, communicate, and evaluate reportable events.

Postmarket Surveillance: Manufacturers must establish a written standard operating procedure for the collection, maintenance, and auditing of data for tracked devices.

Process Changes: SOPs must be updated to record and communicate changes in methods and procedures needed to correct and prevent identified quality problems.

Analogy for Understanding Standard Operating Procedures (SOPs)

If the entire Quality Management System (QMS) is the playbook for running a high-stakes, professional kitchen, the Standard Operating Procedure (SOP) is the chef's meticulous, step-by-step recipe card for every single dish.

The Quality Manual might say, "We prepare world-class Beef Wellington," but the SOP provides the exact instructions: "Step 1: Preheat oven to precisely 400°F (monitored via thermometer X). Step 2: Use Grade A beef only (verified via Certificate of Analysis). Step 3: Sear beef for 3 minutes on each side."

The SOP ensures that whether the head chef or the newest trainee makes the dish, the result is consistent, compliant, and meets the quality standard every time.

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