Work order backlog analysis

A lot has been said about the work order backlog, including a range of key performance indicators for drawing all sorts of information out of it.

So what can it really tell us?

If work is being recorded correctly the maintenance backlog should consist of three separate work order  categories.

1. Work arising from inspections and other corrective work orders.
2. Schedules that have been converted into work orders but have not yet been done, and
3. Schedules that were supposed to be done but have been deferred or rescheduled for some reason. 

There are other areas also. Things like capital maintenance work, replacements and refurbishments, off site planned work and so on... but when you get down to it they all fall under one of the three main categories listed above.

If your company also uses work orders for non maintenance or operations related tasks ... then good luck with that. This post has nothing to do with that. 

So what can these three major categories, and their sub categories, of work tell us? 

Work order backlog as a Scheduling indicator

First of all, and most importantly, it can tell us the accuracy of our scheduling process. If you run a capacity schedule, then slips in schedule compliance can be accurately tracked to either break in work, over runs on scheduled work, or a physical lack of time to do the lower priority work.

I see this level of analysis as being exceptionally important for maintenance planners and analysts. Because it can tell us so much.

If we had break in work then why did that happen? Something for the RCM / asset strategy people to deal with...

If we over ran on the scheduled work then there is likely to be some good reasons why somewhere. Was it excessive delays? Overly optimistic work estimates? Waiting for something? (Parts, machines, resources, tools, etcetera...)

And if we ran out of time for the lower priority work then why did that happen? Were people absent? Was there a reduction in scheduled labour? Did time get drained away onto other tasks? Again were the estimates too optimistic...? And so on...

Every schedule, in fact every missed scheduled task, provides a trained eye with a great opportunity for improvement. 

Two ways to evaluate planning

Within the work order backlog there are two very strong methods for measuring the effectiveness of the companies planning. For readers of this blog I don't think I need to go into detail about the importance of planning and scheduling... I am pretty sure we all get it.

But I will just run over the difference as I like to speak about it if that's okay.

Planning is what we need to do and the "stuff" we need to use to do it with, and scheduling is when. At their simplest this is what the two sides of the activity represent.

So how can the backlog tell me if I am planning well?

First, measure the difference between the actual labour hours and the estimated labour hours. This is a killer measure that tells us immediately if we are planning the work well.

Particularly if, and many companies do not do this, we are recording delays on work orders. (A silver bullet for work efficiency if anybody really is looking for one)

Actual time divided by estimated time expressed as a percentage. Anything less than 100% means you are going well, anything over 100% means there is some explaining to do.

You can see the opportunity right? Why were the estimates different? Were they wrong in the first place or has something else caused them to differ?

The second way to evaluate planning effectiveness is via the amount of planned work hours in the maintenance backlog.

This is a bit soft and the real science is still out on the "best" figures that you should have. But anecdotally I believe that one to two weeks of full capacity work should exist within the maintenance backlog.

This says a lot about the companies ability to generate work orders, and of the planner to PLAN them. That is, ensure they have procedures, parts, resources and estimates and whatever else they should have.

They get used in two ways. Either a) They are slotted into the maintenance schedule based on their priority, or b) they are left sitting in the maintenance backlog ready to be used at the drop of a hat when the opportunity arises.

If you think two weeks means you have too much backlog work, then fine - go for one. Or if you are just starting to get a hold of things and find it hard to get more than two or three days on top of the planned work in the schedule then fine.

But the measure will be invaluable to see how ready your planners have made your teams.

There are a lot of other measures, and a lot more that the work order backlog is telling us... but I think this is a good start.

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