Guest Column | June 13, 2018

Writing Bulletproof SOPs: Best Practices For Life Sciences Companies

By Joy McElroy

Writing Bulletproof SOPs: Best Practices For Life Sciences Companies

Writing and enforcing effective standard operating procedures (SOPs) can be challenging. Poorly written SOPs are one of the most common causes of deficiencies and observations cited in 483s and warning letters from the FDA. While there are specific issues that often lead back to poor communication, monitoring, or enforcement, an inadequately written SOP will slowly grow into a host of major compliance issues. Companies in regulated industries must know how to organize and deliver information for the intended audience and the intended purpose. Written documents must be clear, concise, and to the point, so that all intended readers understand how to perform their job functions effectively and safely. A well-written and organized SOP gives clear direction and instruction for avoiding deviations. Effectively written and structured SOPs are a necessity for maintaining compliance and manufacturing quality products.

What Is A Standard Operating Procedure?

An SOP is a set of written instructions that documents a routine or repetitive activity that is followed by employees in an organization. The development and use of SOPs are integral parts of a successful quality system, as they provide information to perform a job properly and consistently in order to achieve predetermined specifications and quality end results. SOPs address all requirements to complete the job or process safely and effectively.

Purpose Of Standard Operating Procedures

The FDA and other regulatory bodies such as ISO (International Standards Organization) require companies to write and follow SOPs. The purpose of SOPs is to detail the regulated recurring work processes that are conducted or followed within a company.

  • They document the way activities are to be performed to maintain consistency with technical operations and to support data quality.
  • They describe the analytical processes, validation and qualification processes, and processes for maintaining, calibrating, and using equipment.
  • SOPs maintain quality control and quality assurance processes and ensure compliance with regulations.

Writing SOPs From The End User’s Perspective

Keep in mind that SOPs must be written from a practical perspective. They must be written from the point of view of the reader, the one who will actually use them. SOPs must contain step-by-step instructions that individuals have to refer to in order to complete various tasks reliably and consistently. SOPs must be clear, concise, and to the point. Sentences must be as brief as possible, using simple, everyday terms that are common to the industry. The meaning of an instruction should never be blurred or muddled by using overly technical language or words only understood by a particular profession or group when a simple, clearly understood word or phrase communicates the same message or idea.

Remember to always write an SOP in active voice, presenting the main idea first. Keep in mind the activity or process you are describing. Use simple action verbs such as identify, review, evaluate, or direct. These get the point across without requiring explanation. Never give a choice when writing an SOP. The directions have to be straightforward. If there is a choice to be made, state the situation clearly and say “if this, then do this.” “Must” is always mandatory; do not use words like may or should. “May” gives the reader personal decision-making power or flexibility depending on the context, and “should” is conditional. These words give no tangible meaning. They do not enforce consistent direction or execution of a directive, which is the main goal of a standard operating procedure.


If a complete sanitization cycle has completed and the USP purified water (PW) point of use valves were flushed,

                        A. The operator will complete the sequence as follows:

                        B. The operator will command the USP PW point of use valve flush point to “FINISHED”

                        C. The cycle will complete normally.

If a sanitization cycle has NOT completed and the USP PW point of use valves were flushed,

                        A. The operator must troubleshoot why the return temperature could not achieve and maintain 185°F for 60 minutes.

                        B. After the problem has been corrected, the operator must take the system out of the sanitization cycle as follows:

                        C. The operator will command the BMS point SANITIZ to “DISABLED.”

If the procedure is more like a map with an almost infinite number of possible outcomes, a flowchart may be your best bet. This is the format you should opt for when results aren't always predictable.

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Formatting An SOP

All SOPs must address the following:

  • Header
  • Purpose
  • Scope
  • Responsibilities
  • Definitions
  • Procedure
  • References and Related Documents
  • Appendices
  • Revision History
  • Approval Signatures

The header must include the title, document number, and version. It must clearly identify the activity in question and contain any relevant keywords.

The purpose must define the intent of the document and be no longer than one or two sentences. It needs to be detailed enough so end users can quickly recognize what process or procedure the document addresses, with no other detail included.

The scope defines to whom or what the SOP applies. The scope must not leave anything for interpretation. Clearly spell out what and who is and is not in the scope. All readers must have the same understanding of the starting point and the coverage of the SOP.

The responsibilities section defines the roles responsible for executing activities within the procedure. If there are a large number of responsibilities listed, it is best to tighten the scope and create multiple or sub-SOPs to complete the task.

The definitions section clarifies any unfamiliar terms for the reader and spells out any acronyms or abbreviations that are used. Be aware that while a term may be familiar to you, the author, it may not be familiar to the reader. In addition, a clearly defined SOP will help auditors and regulatory authorities understand the procedure without requiring in-depth examination or investigation during an inspection.

The procedure must contain step-by-step instructions as much as possible. Keep in mind, however, people tend to ignore long SOPs because they cannot remember more than seven to 13 steps at a time. If your SOP goes beyond nine or 10 steps, consider these solutions: 

  • Break the long SOP into sections or several logical sub-job SOPs
  • Write an accompanying shortened SOP that lists only the steps but not detailed explanations of those steps
  • Make the long-form SOP a training document or manual to supplement the shorter sub-job SOPs.

Be sure your SOP holds to company standards set forth in the written procedures. The FDA wants to know that standards meet compliance expectations without containing so much material that it may actually create a compliance risk. To avoid this, the SOP may be broken down into major steps, individual action steps within major steps, and notes. Major steps must only include steps necessary to complete the task. Notes must be written separately and be given for clarity, responsibilities, or warnings.As mentioned previously, a long, detailed SOP may be broken down into sections or sub-SOPs as necessary.

The appendices may contain flowcharts and/or diagrams to aid in explaining the procedure during an audit or for training employees. They are most helpful to readers who are visual learners.

The revision history records changes made to a procedure and justifies the change or the reason why the procedure was created.

The approval signatures are typically found on the cover or the back page. SOPs require various approval signatures. Key roles in play include the author, reviewer, management approver, and quality assurance reviewer/approver. Remember, per 21 CFR Part 211, the quality assurance unit is required to approve all procedures that may impact “the identity, strength, quality, and purity of the drug product.”

Team Writing SOPs

The team writing approach for SOPs is very advantageous because it ensures that comprehensive knowledge acquired from different perspectives is applied to the SOP. It creates "buy-in," which increases the likelihood that the SOPs will be implemented under the guidance of the initiator. Employees like to feel they have contributed and are a part of the SOP writing process. Be mindful that employees who perform the tasks are the experts. They know the best ways to get the job done most efficiently, so it is advantageous to have their input. Team writing also trains trainers, the people who write the SOP. Having participated in the in-depth decision making about the SOP, the initiator knows it intimately and is more likely to be an effective trainer. Team writing involves people from diverse parts of the operation as a whole, which helps to ensure that new and modified processes are implemented in the SOP. It also encourages employees to follow the SOP and listen to the coaches, because the employees know that the initiator invested time and effort on their behalf. 

Ideas To Keep In Mind

When writing SOPs, there are a few ideas worth keeping in mind:

  • How much someone knows about an entire process or job affects the way he or she does the job.  
  • All jobs differ in the number of steps required to complete properly.
  • SOPs should be as lengthy as necessary for a specific job.
  • Shortchanging someone by providing short and incomplete SOP sets up them up for failure.
  • Write an SOP to satisfy the definition and purpose of the SOP -- not a standard company format that no one has thought about in years.
  • Incorporate safety, health, and environment into the traditional “how to operate” or “to do” steps. 
  • Teach the reader comprehensively so that he or she has a complete picture of the responsibilities for doing a job well.
  • This knowledge base simplifies follow-up training.
  • Readers do not read all the steps before starting on step one.

Many people read one step, perform it, and read the next step, perform it, and so on. Get around this habit by forecasting future effects and steps at certain points in the SOP to tell the reader things they must know in advance, such as upcoming steps that require caution and precision or timing and assistance and personal protective equipment. 

SOP Distribution

The FDA requires that companies distribute SOPs in a timely manner and that each employee validate the receipt and understanding of the SOP. If an organization is particularly large, this may require an electronic data management system (EDMS). This system must comply with all Part 11 regulatory requirements, including secure access for program monitoring and management. It must store data in an audit-ready format that is quickly available for auditors during an inspection.

"Failure to follow written procedures" appears frequently in 483 citations and warning letters –– a clear indication that employees neither understood nor applied the necessary knowledge to fulfill their responsibilities. Be sure to provide the appropriate training before SOPs become effective. Having well-organized training programs is a must. Employees must demonstrate comprehension of the SOP by reading and performing the task.

All SOP training programs should include testing or evaluations that establish an employee's level of comprehension of all applicable SOPs. Online-based testing programs are a great way to give managers and supervisors immediate access to this information and to promote a quick response to knowledge gaps. Likewise, testing documentation demonstrates to auditors that the organization is committed to effective employee education rather than document distribution alone.


Writing and enforcing effective SOPs is critical to an organization’s success as a quality manufacturer as well as to regulatory compliance. Poorly written SOPs are the source of most 483s and warning letters issued by the FDA. SOPs must be written in a brief, concise, to the point, comprehensible manner. The best idea to keep in mind when writing an SOP is to write as if the reader has no prior knowledge. This will allow you to write in simple terms common to the industry. Always write in active voice using present tense verbs. Never give the reader a choice by using words like may or should. Be direct, decisive, and to the point. A well-written and organized SOP will give clear direction and instruction for avoiding deviations and ensure the manufacture of quality products.

About The Author:

Joy McElroy is the founder and principal consultant at Maynard Consulting Company, which provides services in validation engineering, process engineering, quality control, and quality assurance. McElroy began her career in the pharmaceutical industry performing environmental monitoring and sterility testing, and then moved into a supervisory role overseeing quality control. From there, she moved into quality assurance, and then into equipment qualification and process validation. In addition to consulting, she also develops and delivers webinars, on-site training, and seminars in areas such as technical writing, equipment qualification, cleaning validation, FDA audit preparation, and more.

McElroy earned her B.S. in zoology from North Carolina State University. You can reach her at  or connect with her on LinkedIn.