Which one you need, an SOP, a work instruction or a policy
Short answer. A policy says what must happen and why. A procedure says how your business does it, in order. A work instruction covers a single task in more detail. A checklist is a procedure stripped down to what gets ticked in the field. In a shop under twenty people, you almost always want a checklist and you almost never need all four.
Four words for three things
Most confusion here comes from consultants selling a document hierarchy that suits a factory with a quality department. A shop with eight vans does not need four tiers of documentation. It needs the crew to do the job the same way twice.
Policy
A rule that exists whether or not anyone is doing a task. Phone use, drug and alcohol rules, expenses, leave. These belong in a handbook and change rarely, usually because a law changed.
Procedure
How your business performs a job, in the order it happens. Water heater replacement. Panel upgrade handover. This is where almost all the value is for a trade contractor, because this is where two technicians differ and the difference costs money.
Work instruction
One task, more detail, usually tied to specific equipment. Flaring and torquing a line set. In practice, if you are writing one of these you are writing a procedure with more steps, and the label does not change anything.
Checklist
A procedure reduced to what gets confirmed in the field. This is the form your crew will actually use, and it is the format worth writing in from the start rather than deriving later.
Choosing, in one question
Ask what problem you are solving.
- People behaving inconsistently on a job: procedure, written as a checklist.
- People breaking a rule unrelated to a job: policy, in the handbook.
- One piece of equipment being used wrong: procedure for that equipment, with a photo.
- Steps being skipped when someone is rushed: checklist with an acknowledgement, so the skipping is visible.
Why mixing them fails
Small shops often end up with one document trying to be everything: holiday requests on page two and gas line testing on page nine. Both parts suffer.
They change at different speeds. A handbook changes when the law does. A procedure should change whenever someone finds a better way or a callback exposes a gap. Bind them together and procedure improvements wait for a handbook revision, which means they never happen.
They also need different acknowledgements. A handbook is signed once at hire. A procedure is signed per version, per person doing that work. One signature at hire proves neither.
What to write first
Not an inventory of everything your business does. List the last ten things that cost you money: a callback, a damaged floor, a two-star review, a part ordered twice. Each is a procedure that either did not exist or was not followed. Write those, in that order, as checklists of about seven steps.
That is more documentation than most shops your size will ever have, and it takes an afternoon a week for a month.
Keep the record, not just the paperwork
Everything on this page is free to copy. What Intulix sells is the part underneath: a signed, dated, version locked record of which technician read which version, exportable when someone asks. Start free or see pricing.
Common questions
What is the difference between an SOP and a work instruction?
A standard operating procedure describes how a task is done in a specific business, usually across a whole job. A work instruction is narrower and more detailed, covering a single task or piece of equipment. In small shops the distinction is academic and the terms are used interchangeably.
Do I need a policy as well as a procedure?
Only where a rule exists independently of any task, such as drug and alcohol rules or phone use. Those belong in a handbook. Anything describing how work is performed belongs in a procedure.
How long should an SOP be?
Around seven steps. Beyond that people skim, and a skimmed procedure produces the same behavior as no procedure while giving you paperwork that suggests otherwise. If a task genuinely needs fifteen steps, it is two procedures.