Why Manufacturers Absolutely, 100% Need APS (Advanced Planning & Scheduling)

Mike Liddell, CEO of Lean Scheduling International and Author of “The Little Blue Book on Scheduling”

I am often asked for a brief explanation of why a manufacturing company would need an APS system, and over the years, I must admit that I have struggled with a simple explanation.

Recently, however, I have concluded that there is a very simple way of doing this using one word: “connectivity.” I often say that a plant is like a gigantic Rubik’s cube in that every time you move or change something, you potentially change what happens to every order, machine, operator, tool, and raw material. The problem is that without an APS system, you have absolutely no way of knowing what that impact is. In short, you have no way of knowing cause and effect.

Let me draw a simple analogy for you. Say you and your spouse want to go to the Bahamas for your summer vacation but your kids want to go to Disney in Orlando.

Assuming that you cannot afford to do both, then you must make a decision. Whatever your decision is, you will probably start by making sure that you can find a date where there are no work conflicts, no school conflicts, no flight conflicts, and no hotel conflicts.

This takes considerable time and effort, so you can imagine what happens if, at the last minute, your flight is cancelled, and you cannot even get to your destination. You must go back to square one and go through the whole process from scratch because if there is a conflict with even one area, then you will not be able to go on vacation.

Now, if you imagine that you must do this hundreds of times a day then you will start to get a sense of what is going on in your plant. Every time you get a new order, change an order, a machine breaks down, a job takes longer than estimated, an operator doesn’t show up, or you just change the sequence of work at a machine, your whole world can change.

Even today, most schedulers rely on Excel to create detailed schedules, but the problem with Excel is that it cannot automatically recalculate your schedule to reflect any of the changes mentioned in the previous paragraph. If you try and recalculate everything manually then this could take you several hours, and by the time you finish, everything (or maybe even just one thing) has probably changed again.

One of the biggest factors that impacts your results is how you sequence events in your plant. Excel typically will only load a resource in time buckets, so it has no ability to understand the impact when you change the sequence of events at a machine. Yet changing the sequence at a machine is probably going to have the biggest impact on what changes, what you produce, and how you deliver orders to your customers.

Of course, you can keep on guessing, but how will you know when you make a good decision and when you make a bad decision? The answer is you won’t, so all you can do is play a guessing game without any ability to see the potential impact when you make decisions.

 The good news is that a good APS system will do all this for you and do it in a few minutes. Why would you not want this ability knowing that some of the companies you are competing against have it?

You can find more about this topic and others in Mike Liddell’s book “The Little Blue Book on Scheduling” or by contacting Mike at [email protected].