Tipsblog

Maintenance Tip

Work Instructions by Equipment or by Task?

When developing work instructions at some point the question arises as to if the tasks should be grouped so that one piece of equipment is worked on, or, one type of task is performed on multiple items of equipment.

For example:

(A)- Check belt tensions on all conveyors
Or
(B) - Check belt tension, rollers, scrapers etc on conveyor CV004

Obviously we need to set up work instructions to facilitate least possible total shutdown requirements AND most cost effective method AND effectiveness of task.

There are pros and cons for both methods, but some general observations are :

Per Item of Equipment

Pros
-Less ‘ramp time’
-Greater potential for ‘other’ potential problems to be identified and acted upon

Cons
-Greater potential for individual check tasks to get ‘missed’ (seen as not important)
-Greater potential for lower quality of ‘check’ on some components
-Potential increased ‘tool time’ due to unfamiliarity of individual tasks
-Potential increased ‘tool time’ as maintainer may not have all required tools on him for all tasks

Per Type of Task

Pros
-Higher quality of ‘check’ task on that individual task
-Less potential for ‘check’ task to be ‘missed’ (importance implied)
-Potential reduced ‘tool time’ due to familiarity / repetition of task
-Potential reduced ‘tool time’ as maintainer will have all required / correct tools on him (after first one)

Cons
-Increased ‘ramp time’
-Greater potential for ‘tunnel vision’ can occur

The weighting / likelihood of the above pros and cons varies for different businesses / workforces, and considering these can help make the right decision.

Tip provided by ARMS Reliability Engineers