This is a free sample from the course Implementing Maintenance Planning & Scheduling.
In this lesson, we’ll discuss why scheduling is a continuous process and I will compare scheduling to a process of a conveyor belt with buckets of work that the scheduler needs to fill. Looking at scheduling like this will help to understand how the continuous development of a frozen weekly schedule works, and how it combines with developing a draft schedule for future weeks.
The Key Points of this lesson are:
This video is one of the 48 video lessons contained in the course Implementing Maintenance Planning & Scheduling (PS100). Some of the other things we discuss in this module are:
All right, welcome to lesson five of module six in which we’ll look at scheduling as a continuous process. Now this is going to be a short lesson with a couple of key points. The first is that you need to see scheduling as a continuous process. And in this lesson, I will compare scheduling to a process of a conveyor belt with buckets of work that a scheduler needs to fill. Looking at scheduling like this will help you to understand how the continuous development of the frozen weekly schedule works and how it combines with developing a draft schedule for future weeks. The second key point is that the scheduling process can only work if the maintenance supervisor and the maintenance planner play their parts in the process. And using that conveyor belt analogy will make this very, very clear.
Now in this module we’ve talked a lot about scheduling and we’ve talked about how your scheduling would build the frozen weekly schedule. And in this lesson I want to take a slightly wider look at the process of scheduling and I want you to imagine your scheduling process as a conveyor belt. Your weekly schedules are represented as buckets on this conveyor, and with the size of the bucket representing the amount of labor you have available. The current week is week one, next week is week two, et cetera. And as time progresses, the buckets that are sitting in the future come closer to you. They’re moving to the left on the conveyor belt. And as a scheduler, it is your job to fill these weekly buckets with the maintenance work orders. And that’s what you see here.
The weekly buckets are now partially filled, overfilled, perfectly filled with work orders. The horizontal blocks are PMs and the vertical blocks are CMs. White blocks represent work orders that still require planning. Blue blocks is work that is fully planned. And green blocks is work that is ready to execute. Now remember, those statuses are maintained by the planner but it’s down to the scheduler to make sure the work is sitting in the right bucket. Of course the scheduler does need to work within any constraints set by the planner. The planner has set a job so that it cannot start before week eight, then the scheduler can’t just go ahead and schedule that for week six. But the scheduler can delay it to week nine or week 10.
So one of the things we want to see here on this conveyor belt is that we only want to see green blocks in the current week, and of course mostly green in next week, week two, and the week after. And as you look further out, you’ll see that you see less and less green and more and more blue. So less and less work is ready to execute and more and more work is fully planned but we’re still waiting on parts. And as we go out further, you’ll see that most of the work is actually white, which means that the work still actually needs to be planned.
And if you look in the current frozen week, you’ll see indeed that there are only green blocks in this bucket. And that means we only have ready-to-execute work sitting in there. And the bucket is neatly filled to the top, which means we are utilizing our available labor capacity. And when you look in the following weeks, the draft weeks, which in this case are the next three weeks, you can see that next week is neatly filled and mostly green with just one blue block, which means that it’s fully planned, but the planner has not yet been able to confirm that the materials are here and therefore hasn’t been able to mark that specific work order as ready to execute. And that means that before the frozen weekly schedule is issued next week, the planner needs to confirm to the scheduler, or in the CMMS, that that work order is indeed ready to execute or not. And if not, then the scheduler will basically need to defer that job from week two to, say, week three or week four and bring a ready-to-execute, a green job, from a future week forward.
So let’s assume we swapped a job that’s sitting in week two that is fully planned but not yet ready to execute with the ready-to-execute job that is sitting in week-three bucket. So now week two is good to go, just in time for our weekly schedule review meeting later this week. But the scheduler also needs to have a look at week three and week four. There’s still a few job’s in there that still require planning, i.e. they’re white, and the scheduler will have to see if these should be deferred to a later week, like for example week six or week seven, especially week seven where our bucket is still quite empty and we have plenty of labor capacity. Now it could be that some of those jobs just don’t need much planning, and maybe even just parts that are in stock, in which case they could be left in weeks three and weeks four, especially if they were high-priority work.
But the question is, unless they have been planned, how would you know, right? So the sensible approach will be to move all white work orders, all white blocks, out of week three and week four and only leave ready-to-execute, the green blocks, and maybe some high-priority, fully-planned work, blue blocks, where we would expect to get the outstanding services materials confirmed before their respective week commences. Essentially what I’m saying here is that obviously for a frozen week all the blocks need to be green. That’s the current week. For week two, week three, and week four, you really want to see mostly green blocks, especially in week two, and then some blue blocks for week three and week four. And only by exception would you allow to have some white blocks still sitting in week three and week four. Only by exception.
So once we’ve done this, our conveyor belt will be like what you see here. We’ve moved all the white blocks that still require planning to future weeks and we’ve kept a number of fully-planned work orders, blue blocks, in the draft schedules for week three and week four, because they are high-priority work that is best done combined with some other work that is already scheduled in those weeks. And that’s fine. Next week, in week two, the scheduler is going to take another view on this, and if the planner has not been able to convert those fully-planned work orders to ready-to-execute, we’re simply going to reschedule them to future weeks and bring some other ready-to-execute work forward.
But as part of this look, the scheduler will also have noticed that capacity is quite reduced in week four and we have loaded too much work in that week. but in this case, the scheduler has decided not to change that just yet until he or she knows exactly what work will be ready to execute. At this point, it’s fine to have a week that is three weeks away to be overloaded to some degree. That is reality. And I don’t want to just show you a perfect picture because these things are going to happen in your plant and it’s up to your scheduler to deal with these capacity issues on a weekly basis.
Now when you look at scheduling like this, as a conveyor belt where the buckets are moving to the left and coming closer, you can also immediately see why it’s so important that your planner maintains accurate work order statuses for work that is fully planned and for work that is ready to execute. Because your scheduler totally relies on those work order statuses to create a high-quality, robust weekly schedule and to create draft schedules for future weeks. You can also see that it’s key for your maintenance supervisor to advise the scheduler of any capacity changes so that the size of the bucket is adjusted. If that’s always done at the last moment, that creates a lot of rework for your scheduler. And that rework will result in your scheduler having less time to put together a solid draft schedule for future weeks.
One thing I still want to show you is what happens in the scheduling process when we have emergency work break into the frozen week. When we have an emergency job break into the frozen week, we’re going to have work that was ready to execute that we don’t complete. And because emergency work is planned on the fly, we’re going to execute it with lower productivity. So a job that would only take two hours if it was fully planned and ready to go could now easily take six or eight hours as we’re scrambling to get isolations in place, find materials and parts, etc.
And so we’re going to have to reschedule quite a lot of work out of the frozen week, and probably into next week, week two, which then would mean we would need to reschedule work from week two to week three and from week three to week four. So you can see the ripple effect this single emergency job can have because we had to break into the frozen weekly schedule. And you can see how this leads to a lot of work for your scheduler and can potentially upset your draft schedule for the next three or four weeks. This is another reason why it’s so important to protect your schedule and keep emergency maintenance to an absolute minimum.
So when it comes to the role of the scheduler, using this conveyor belt analogy, you can quite quickly see the key roles and responsibilities of the scheduler come through. The first is to maintain our labor capacities, which are here represented by the size of the buckets. Now in reality, of course, you have multiple buckets per week, one bucket per trade. But to simplify the concept of the conveyor belt, I’ve just used a single bucket here.
The second role of the scheduler is to then level the workload by distributing the PM and the CM work across the buckets on the conveyor belt. And when this is done, you want to make sure your scheduler is grouping work together to drive efficiency, both for your crew but also for operations, by minimizing isolations, and of course to minimize equipment downtime. Now, this all needs to be done recognizing the work order priorities and target due dates. And of course the scheduler needs to make sure the frozen week only includes ready-to-execute work and that future draft weeks are mostly ready to execute with some fully-planned work in there. And only by exception should they include work orders that still require planning.
And the last role is for the scheduler to reschedule work from the frozen week if it was not completed. Now that could be due to a break in, as we just discussed earlier, or maybe something else happened that simply stopped us from completing the work this week. Now this is not a full and complete job description of the scheduler of course, but it certainly gives you a good idea of the role of the scheduler and the role the scheduler plays in that continuous planning and scheduling process.
And that brings me to the end of this lesson. As we discussed, scheduling really is a continuous process. It’s a conveyor belt of buckets of work that the scheduler needs a continuously fill to capacity based on priority, due dates, et cetera. We also saw how important it is for the maintenance supervisor to advise the scheduler of future labor capacities, the size of the buckets, and for the planner to make accurate work order statuses for fully-planned and ready-to-execute work. If the people in either of these roles are not fulfilling their role, or not consistently or not accurately, your scheduling process will suffer. This is really important to keep in mind and it is really important to make sure your maintenance planner and your maintenance supervisor understand their role in the scheduling process.
Learn what maintenance planning & scheduling is, how it creates value in an industrial plant and how to successfully implement it.
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