Creating and Preparing SOPs for Production: A Guide for Manufacturers

Standard Operating Procedures (SOPs) are one of the key components that ensure consistency when fabricating parts and throughout final assembly. They provide clear, step-by-step instructions that ensure every operator performs tasks the same way, no matter the shift, team, or location. Without the proper SOP, tasks will be carried out the way an operator thinks it should be done, which often leads to inconsistency and parts failing. 

For manufacturers, creating and preparing SOPs is not a task that should be left until the last minute. They need to be developed before mass production begins so that workers have clear guidance and the production line can run smoothly from day one. Usually, during the production validation test (PVT) build is the best time to create these SOPs. Then, during the PVT or pilot run, you can make sure that the workers follow the SOPs correctly and make any enhancements to the SOPs. 

This blog will explore when to create SOPs for production, the level of detail they require, who is responsible for making them, and why they are essential for success. By the end, you’ll have a clear understanding of why SOPs are crucial and how to create them in a way that is both practical for operators and reliable for scaling production.

When to Create an SOP for Production

An SOP should never be treated as an afterthought once production is already underway. The right time to create an SOP is before a product enters mass production, ideally during the later stages of validation and pilot runs. This ensures that any assembly steps, tooling requirements, or quality checkpoints are tested and refined while volumes are still low.

If SOPs are delayed until after production starts, operators are left without clear instructions, often relying on assumptions or verbal guidance. This creates inconsistencies from worker to worker and shift to shift, increasing the risk of defects, rework, and missed delivery deadlines. Early preparation allows the SOP to be part of the production readiness process, aligning with quality checks and operator training.

By having SOPs ready before the first production run, manufacturers set the foundation for repeatability and stability. Operators know exactly what to do, engineers have documented processes to optimize, and managers have a clear framework to evaluate performance and identify issues quickly.

The Goal of an SOP in Manufacturing

The primary goal of an SOP is to create consistency and repeatability on the production line. Every product should be assembled, inspected, and packaged in the same way, regardless of who is operating the station or which shift is running. This ensures that customers receive the same quality standard with every order.

Beyond consistency, SOPs serve several important functions. They are an essential training tool for new operators, reducing the time it takes for them to become up-to-speed and minimizing the risk of mistakes during onboarding. They also create accountability by establishing a reference document that makes it clear how each task should be performed.

Another key goal is compliance with quality standards. Many certifications, such as ISO 9001 or IATF 16949, require documented procedures to prove that a company is in control of its processes. SOPs provide the framework for audits and demonstrate to customers and regulators that production is structured and reliable.

How Detailed Should an SOP Be?

An SOP should be detailed enough that any trained operator can follow it without confusion, but not so overloaded with information that it becomes impractical to use on the line. The balance lies in making the instructions clear, precise, and accessible.

At a minimum, SOPs should include:

• Step-by-step instructions for each process, written in the operators local language.

• Visual aids such as photos, diagrams, or CAD renderings to show the correct orientation of parts or proper assembly methods.

• Tools, jigs, and fixtures required at each station, so operators know exactly what equipment to use.

• Quality checkpoints that highlight inspection steps or measurements operators must confirm before moving forward.

Well-prepared SOPs also consider the reality of the production floor. If instructions are vague, workers may interpret them differently. If they are too technical, operators may not understand them. The goal is to make them practical guides for the people actually assembling the product.

In addition, SOPs should be living documents. As products are improved, tools are updated, or processes change, the SOP must be revised to reflect those updates. This ensures that the document always matches the current production reality.

Who Is Responsible for Creating SOPs?

The responsibility of creating SOPs typically falls on the engineering team and at EPower, the person in the engineering department that’s responsible for this is the Production and Industrial Engineering (PIE) team. These engineers are closest to the production process and understand the technical requirements, workflow, and tools needed to ensure smooth operations. Their role is to translate the product design and process plan into a step-by-step guide that operators can reliably follow.

While PIE owns the drafting and documentation, they need to work with other departments as well. Input from other engineers, quality teams, production operators, and the customer is essential. Engineers may define the technical standards, but operators provide practical feedback on what works best on the line. Quality teams, meanwhile, ensure that the SOP aligns with inspection standards and compliance requirements.

This collaborative approach ensures the SOP is not only accurate from an engineering perspective but also realistic for day-to-day use. A well-prepared SOP reflects the collective knowledge of multiple departments, making it a more reliable document for achieving production goals.

How to Prepare SOPs for the Production Line

Creating an SOP doesn’t end with writing instructions on paper, it needs to be prepared, tested, and refined so it works seamlessly on the production floor. The process usually starts with a draft version, created by the PIE team, which outlines the step-by-step tasks, required tools, and inspection points. This draft is then tested during pilot runs or low-volume builds to confirm that the instructions are clear, practical, and complete.

During this testing phase, it’s important to gather feedback from operators. If workers find a step unclear or if the sequence slows down production, adjustments should be made before the SOP is finalized. Including images, such as photos of the workstation setup, arrows indicating part orientation, or screenshots from CAD, helps operators quickly grasp instructions without needing to read long text.

Once validated, the SOP should be made easily accessible. Copies can be laminated and posted directly at workstations, or digital versions can be displayed on monitors along the line. SOPs should also be integrated into training programs, so new employees learn the correct processes from day one.

Finally, SOPs should be treated as living documents. As equipment changes, tooling is updated, or the product design evolves, the SOP must be revised accordingly. Regular reviews and audits ensure the instructions stay accurate and continue to reflect real production practices.

Why Companies Cannot Overlook SOPs

Skipping or neglecting SOPs might save time in the short term, but the long-term costs are significant. Without SOPs, production becomes inconsistent, as operators rely on personal judgment or verbal instructions. This often leads to quality issues, rework, and delays, all of which increase costs and damage a brand’s reputation.

SOPs also play a critical role in scaling production. A company may manage with informal guidance during prototype or pilot stages, but when volumes increase, even small inconsistencies compound into major problems. Having SOPs ensures that a product can be manufactured reliably at higher volumes without sacrificing quality.

Another reason companies cannot overlook SOPs is their importance in customer and regulatory compliance. Many industries require documented processes to demonstrate control over production. In an audit, missing or outdated SOPs can raise red flags and jeopardize certifications like ISO 9001 or IATF 16949.

Ultimately, SOPs protect both the manufacturer and the customer. They reduce risk, improve efficiency, and provide confidence that every product meets the required standards. Overlooking them means putting both operations and customer relationships at risk.

Conclusion

By creating SOPs before mass production begins, companies set the stage for smoother operations, better training, and fewer risks on the line. With clear goals, the right level of detail, and ownership by the PIE team in collaboration with quality and production, SOPs become practical guides that operators can rely on every day.

The companies that invest the time to prepare thorough SOPs see the benefits in fewer defects, stronger compliance, and greater efficiency as they scale. On the other hand, those that overlook SOPs often face costly delays and unpredictable results.

In short, SOPs are not just about compliance or paperwork, they’re about building a reliable production system that delivers the same result every time. By treating SOP development as a critical step in the journey from prototype to mass production, manufacturers ensure that their teams are aligned, their processes are controlled, and their products consistently meet expectations.