Work instructions for maintenance: how they differ from procedures and job plans, the parts of a good step, and keeping them current
What a work instruction is and how it differs from a procedure, a job plan and a form, the parts of a good step from the action and key point to the value and its source, how to write one that gets used, the formats, and the triggers that keep instructions current. With a drawing of one step opened out.
Key takeaways
- A procedure says what is done, by whom and when. A work instruction says how one task is done, step by step, by the person doing it. A job plan in the CMMS says what the job needs and points to the instruction.
- A good step has one action starting with a verb, the key point that makes it done right, the reason for the key point, any value with its source, a marked up picture, and a check before moving on.
- Instructions are written with the people who do the task, tried on the equipment, and kept short. A task that needs forty steps is usually several tasks.
- An instruction is only as good as its last review. Feedback from the job, equipment changes, failures and manufacturer bulletins should all trigger one.
- Values such as torques, clearances and fill quantities come from the manufacturer or the engineering standard and are referenced, never copied from memory.
A gearbox on a conveyor drive fails three months after a coupling change. The investigation finds the coupling bolts were tightened in sequence round the circle instead of in a star pattern, pulling the hub out of line. The tradesperson had done it the way they had always done other couplings. The work instruction existed, ran to eighteen pages, and nobody on the crew had read past the hazard section.
This guide covers work instructions for maintenance: how they differ from procedures and job plans, what goes in a good step, how to write and test one, the formats, and how to keep them current. It sits beside the guides to the maintenance job pack, which carries the instruction to the job, and preventive maintenance programs, which set which tasks are done. The standards named are reference points.
Anatomy of a step
Most of what makes a work instruction useful is in the step. One action per step, starting with a verb, so it can be done and ticked off. The key point, which is the thing an experienced person knows that makes the step done right. The reason for the key point, because people skip what they do not understand. Any value, with where it came from. A picture of this equipment at this step, marked up. And a check before moving on.
Those parts come from the job instruction method used in industry since the 1940s, and they still work because they capture what a good tradesperson would tell a new one standing beside them at the job.
The key point is the reason the instruction exists. If a step has no key point, it may not need to be in the instruction.
Procedure, instruction, job plan and form
Sites often blur these, and documents grow until nobody reads them. Keeping each to its job makes all of them shorter. The procedure describes the process across roles. The work instruction describes one task for the person doing it. The job plan in the CMMS says what the job needs and points to the instruction rather than copying it. The form records that it was done.
| Document | Answers | Scope | Example |
|---|---|---|---|
| Procedure (SOP) | What is done, by whom, and when, across a process | A department or several roles | How defects are raised, prioritised and approved |
| Work instruction | How one task is done, step by step, by the person doing it | One task on one kind of equipment | Replacing the coupling on a conveyor drive |
| Job plan | What a maintenance job needs: steps, trades, hours, parts, tools, permits | One repeatable job in the CMMS | The six monthly drive service, pointing to the instruction |
| Form or checklist | The record that the task was done and what was found | One completion of the task | The completed drive service checksheet |
What goes in a step
Each element of a step does one job. Values such as torques, clearances, fill quantities and settings come from the manufacturer's manual or the engineering standard, and the instruction names the source so the value can be checked when the manual changes.
| Element | What it holds | Example |
|---|---|---|
| Step number | Its place in the sequence | 4 |
| Action | One action, starting with a verb | Tighten the coupling bolts |
| Key point | What makes the step done right, the part an experienced person knows | In the sequence shown, in three passes |
| Reason | Why the key point matters, so it is not skipped | Uneven tightening misaligns the hub |
| Value or limit | The number the person must hit, with its source | Torque from the manufacturer's manual for this coupling |
| Picture | A photo or drawing of the equipment at this step, marked up | The bolt pattern with the sequence numbered |
| Check | What to confirm before moving on | Runout within the limit on the dial indicator |
Writing one that gets used
Instructions written at a desk from the manual read well and fail at the job. The ones that work are written with the people who do the task, tried on the equipment, and cut down to what matters. IEC/IEEE 82079-1 sets out general principles for instructions for use, and its points on knowing the audience, plain language, consistent terms and pictures apply as much to a site's own instructions as to a manufacturer's.
- Start from the task done well by the best person on the crew, watched and photographed.
- Keep each instruction to one task. Split long ones into several.
- Put hazards and controls at the step where they apply as well as at the top, and point to the isolation and permit requirements rather than repeating them.
- Use the equipment's tag and the site's names for parts, the same words as the CMMS and the drawings.
- Use photos of the actual equipment, marked up with arrows and numbers, not catalogue images.
- Have someone who has not done the task follow it on the equipment before it is approved.
- Number, date and approve it, and keep one controlled copy.
Formats
The format should suit where the task is done. A one page visual instruction suits a short task done often. A longer overhaul suits a printed document in the job pack, marked up as the job goes. Mobile instructions are always current and can record each step, but need a device that works in the field.
| Format | Strengths | Weaknesses |
|---|---|---|
| Text document | Easy to write and control | Long, hard to follow at the job, pictures added as an afterthought |
| Visual one page instruction | Fast to follow, pictures carry most of the meaning | Only suits short tasks of ten steps or so |
| Mobile or tablet | Always current, video possible, steps can be signed off and recorded | Needs a device in the field, and screens are hard to read in bright light or with gloves |
| Printed in the job pack | Works anywhere, can be marked up | Can be out of date unless printed from the controlled copy for each job |
Keeping them current
An out of date instruction is worse than none, because it is trusted. Instructions are controlled documents under the site's document control, and a change to the equipment through management of change should list the instructions it affects. The most useful trigger is feedback from the job: a line on the job pack or at close out saying which step was wrong or missing.
| Trigger | What it covers |
|---|---|
| Feedback from the job | Steps that were wrong, missing or out of order, written on the pack or entered at close out |
| A change to the equipment | A modification, a different make of part, or a new tool, through the change process |
| An incident or failure | Where the task, or how it was done, contributed |
| A new standard or manufacturer bulletin | A changed value, limit or method |
| The review date | A fixed interval for instructions that are rarely used, so they are still right when needed |
Where work instructions go wrong
- Long documents that mix the process, the training and the task, so nobody reads them at the job.
- Steps without key points, so the instruction says what any tradesperson already knows and misses what matters.
- Values copied from memory or an old manual, with no source.
- Catalogue pictures instead of photos of the site's own equipment.
- Instructions written at a desk and never tried on the equipment.
- Copies printed months ago still in use after a revision.
- Feedback from the job collected and never acted on.
Common questions
What is a work instruction?
A work instruction is a document that tells the person doing a task how to do it, step by step. It covers one task, such as replacing a coupling or changing a filter, on one kind of equipment, and includes the actions, the key points that make each step done right, values and limits, pictures and checks. It sits below procedures, which describe the process, and is usually linked from the job plan in the CMMS.
What is the difference between an SOP and a work instruction?
A standard operating procedure describes a process: what is done, by whom and when, often across several roles. A work instruction describes how one task within that process is done, step by step, for the person doing it. A procedure for defect management might say who raises, prioritises and approves defects. A work instruction would say how to change a particular pump seal. Many sites use SOP loosely for both, which is one reason documents grow too long.
What should a work instruction include?
A title naming the task and the equipment, the scope, the hazards and controls with a pointer to the isolation and permit requirements, the tools, parts and consumables, then numbered steps. Each step has one action, the key point and its reason, any value or limit with its source, a picture and a check. It ends with the checks before return to service and what to record. It carries a document number, revision and approval.
Is there a work instruction template?
A template is a fixed layout with a header for the task, equipment, revision and approval, a section for hazards, isolation, tools and parts, then a table of steps with columns for the action, key point, reason, value and picture, and a section for return to service and records. Using one layout for every instruction on a site matters more than which layout is chosen, because people learn where to look.
How detailed should a maintenance work instruction be?
Detailed enough that a competent tradesperson who has not done this task on this equipment can do it right first time, and no more. Steps that any tradesperson knows do not need spelling out. Steps where the experienced person knows a trick, a sequence, a value or a trap do. If the instruction runs past a few pages, it is usually several tasks, or it is repeating the training the person should already have.
Key terms
Plain-language definitions from our glossary for the concepts this article leans on.
Standards and further reading
Related case studies and tools
- Work management and scheduling uplift (case study)
Related reading
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