If you've started building out your business documentation, you've probably run into both terms: Standard Operating Procedure (SOP) and Work Instruction. They're related but distinct, and using them interchangeably creates confusion in your documentation system.
The Simple Distinction
An SOP answers the question 'what needs to happen and who is responsible?' A Work Instruction answers 'how exactly do I do this specific step?' SOPs operate at a higher level — they document a full business process, define roles, set quality standards, and reference compliance requirements. Work Instructions zoom into a single task within that process.
An Example
Imagine you're a retail store. Your Inventory Receiving SOP covers the end-to-end process: who receives deliveries, how quantities are verified against purchase orders, how items are labeled and stored, and how discrepancies are reported. Within that SOP, step 4 might be 'Scan items into inventory system.' The Work Instruction for that step explains exactly how to use the scanning software — the specific buttons to press, what error codes mean, and how to handle exceptions.
- SOP: covers the full process across multiple roles and steps
- Work Instruction: covers one specific task in granular detail
- SOPs reference Work Instructions when a step requires deep technical detail
- Not every SOP step needs a Work Instruction — only the complex or high-error-rate ones
When to Use Each
Use an SOP when you need to document a complete business process — onboarding a new employee, handling a customer complaint, processing payroll, or managing inventory. Use a Work Instruction when a specific step within that process is complex enough that it deserves its own dedicated how-to document.
For Most Small Businesses, Start With SOPs
If you're just starting to build your documentation library, focus on SOPs first. Work Instructions are useful at scale, but for a business with under 50 employees, a well-written SOP with detailed procedure steps often covers everything you need. You can always extract individual steps into standalone Work Instructions as your documentation matures.