Scheduling – why is it so difficult?


Unlike planning, scheduling involves many people, coordinates many different, independent jobs and determines when each of these jobs will be done and by whom (see “Planning and scheduling – what are they“?).

During our audits, the most common opportunity for improvement is in non-shutdown work scheduling. Shutdown work is so carefully watched, and over-runs are so expensive that it is usually carefully scheduled, sometimes with an excessive contingency allowance to avoid being the “bad guy” who delays the start-up.

To schedule well, the person with scheduling responsibility needs to know:

– what work orders are in the backlog

– the relative importance of all work orders

– the scope of all work order

– the status of all work orders

– how all work orders interact

– the operating schedule

– the current state of the operation

– the availability of the people who will do the work

– the skills and limitations of the people who will do the work

– the availability of special tools and equipment

– many other factors, such as weather and conflicting schedules for training, vacations, etc, etc.

Taking all these factors into consideration and building a good work schedule is no small feat. Add to this that maintenance work schedules, by their very nature, change rapidly and its easy to see that the scheduling function can, and should, take a significant amount of time each day. And of course, there is always a desire to keep tradespeople on the highest priority work which may be very difficult if there are multiple trades, job classifications or pay rates that limit scheduling flexibility. For more on this problem, see our article “The high cost of restrictive practices” .

One essential prerequisite for good scheduling is a well-managed backlog which requires continuous, active and cooperative input from both Maintenance and Operations leaders.

Probably the greatest obstacle to good scheduling is a concern about how a schedule will be perceived by the people who will do the work. The schedule shows the tradespeople how long it is expected they will take to do each job, and they may, often for good reason, disagree. Encourage and use their input!

If a new scheduling system is being introduced, it should be explained that the purpose of a schedule is to provide a better service to operating customers by allowing them to confidently schedule their operation. It will also increase the amount of work done, and this will be achieved by reducing waiting times and other wasted activities, such as frequent trips to the Storeroom, not by expecting people to work harder.

Work order estimates are normally established before it is known who will do the work, and should challenge a skilled and motivated tradesperson who has extensive experience in the work to be done and no physical limitations. There are few people like this. When the work is scheduled and the names of tradespeople assigned, the estimate MUST be adjusted to reflect the skills and limitations of these tradespeople. Sometimes, for training purposes, two people will be assigned to a job that could be done by one.

A common mistake is to assign additional people to an entire job, simply because a small part of the job, e.g. a heavy lift, needs extra people. This is a very poor practice and one that reinforces bad habits.  A good scheduler will schedule additional people only for the time they are needed, perhaps by scheduling two jobs in close proximity to each other. The supervisor then needs to instruct the tradespeople involved to assist each other when called upon.

Where the (common) weekly work scheduling process is in effect, work schedules should be published by the afternoon of the Thursday before the scheduled week. This schedule should contain the highest-priority work that is ready to schedule from the work order backlog (see “Setting priorities“). It MUST be expected that this schedule will change by Monday morning. Schedules must be updated daily, taking into account “found” work, breakdowns and work orders which have taken more or less than the estimated time to complete, which is likely to include most work orders. Daily work schedules should be issued about 2 hours before the end of each work day and shared with everyone who needs to know, including tradespeople and operators. Both Operating and Maintenance supervisors must have a strong discipline to ensure that these daily work schedules are complete and accurate and must resist frivolous changes (e.g. by managers at early-morning meetings).

There are other factors that make scheduling difficult. A common one is the lack of good scheduling functionality that is found in most maintenance computer systems. It puzzles me that the most basic maintenance-management function, that of assigning tradespeople to jobs, is where most maintenance software is very weak. A well-designed spreadsheet can work well, and we have developed some techniques in MS Excel that logically integrate priority-setting, backlog management and scheduling. Our templates and instructions for their use are available on request. For more on the subject of improving maintenance software performance see “Selecting and implementing maintenance software, Pt 5“.

Where there is a reactive approach to maintenance (and no analysis is needed to know if this is the case – “everybody knows”) then scheduling will be discouraging because the scheduler knows that the “promises” made when the schedule is issued will not be kept. In fact, a good, realistic and challenging scheduling process supported by all managers is a very good start to changing the way people think about maintenance, by focusing on what’s planned for next week and avoiding interruptions to current maintenance activity. Where it is known that there will always be some unanticipated work an allowance for this should be made in the schedule, with a goal of reducing this allowance as scheduling improves. The best way to manage this is to record the work that is done each week that is not on the schedule (excluding those “small jobs” that do not justify planning or scheduling – see “Managing small jobs“). Reviewing these unscheduled work orders on a regular basis with a goal of addressing the issues that caused them to be unscheduled will improve scheduling performance. Do avoid measuring “adherence to schedule”, which is quite different from tracking unscheduled work. Adherence to schedule measurements encourage low productivity and bad scheduling habits (see “The hazards in KPI’s“).

The last reason that scheduling is difficult is that it is sometimes assigned to people who either do not have the detailed knowledge of the work as described in the list at the top of this article, or who can not reliably set aside the time required each week and each day to build realistic and challenging schedules. A Maintenance Supervisor is responsible for the current work that is in progress and must deal with any interruptions or breakdowns that occur. For this reason, it may be very difficult for the supervisor to set aside the couple of hours at the same time each week to prepare the weekly schedule, for example. On the other hand, a centralized scheduling position is unlikely to have all the detailed knowledge listed. In my opinion, the most effective scheduling will result if it is assigned to an area Planner, who will soon become familiar with the  capabilities of the people in the crews for which he/she is scheduling. This will, of course, be successful only if the planner is actually working as a planner and is protected from interruptions, such as breakdowns. Also, the final assignment of jobs to tradespeople should always be the Maintenance Supervisor’s responsibility, so any assignments that a Planner/Scheduler shows on a draft schedule should be subject to approval by the Supervisor and revised if necessary.

Bad scheduling habits, such as always assigning two electricians to a job even if it could safely be done by one, are hard habits to change. Eliminating such practices will probably meet with resistance and require strong leadership. There may be a fear that the increased productivity that will certainly result from good scheduling will result in crew reductions, or at least make life difficult for the supervisor who now has to find more work to keep his crew busy, without increasing costs.  The “four steps to change” must be followed to ensure that all affected understand and agree with the reason for the change (see  the articles “Successfully implementing changes” and “The Maintenance Cost-reduction Conundrum“).


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© Veleda Services Ltd

Don Armstrong, President