10 APS Myths
When APS systems first surfaced, many ERP bigots rushed to dismiss this exciting technology without taking the time to understand how powerful it was. Despite the thousands of success stories there are still consultants and ERP vendors who still resort to spreading myths in a losing battle against progress...
This list has been compiled over the last twenty years by a number of seasoned proponents of Finite Capacity Scheduling systems. It has been based on countless success stories and is as valid today as it has ever been. The purpose of reviewing this list is to counter some of the misinformation that has been published over the years about scheduling. Most of these myths have been spread by those who do not understand the nature of either the problem or the solution.
ERP SYSTEMS CAN HANDLE MY SCHEDULING PROBLEMS.
Unless your ERP system comes with an APS system this one is dead wrong. Solving scheduling problems with standard ERP/MRP logic is equivalent to trying to solve a three-dimensional problem with two-dimensional logic. In other words, it simply can’t be done in a timely manner.
IF I BUY SCHEDULING SOFTWARE FROM MY ERP VENDOR I WON’T HAVE ANY DATA INTEGRATION PROBLEMS.
Although this sounds like a good idea it really isn’t. This is because very few ERP vendors, if any, had the skill set needed to develop and implement their own scheduling module, so they went out and bought an APS software company. A detailed explanation as to why this approach does not work can be found in the chapter that is titled “A Simplified History of ERP systems.” in The Little Blue Book on Scheduling.
The short answer is that even if they have successfully integrated APS into their ERP offering (and this is not a given), most ERP companies do not have the skill set to continue developing the APS system and they don’t have the skill set to implement it properly. ERP companies like to deliver cookie cutter modules with some options. This approach does not work in the APS world where your system needs to work at a level of detail that allows you to model the real world you live in. If your schedule makes no sense to shop floor operators then they will not follow it and your APS system will be of no value to you
BECAUSE I HAVE SO MANY CHANGES, MY SCHEDULE IS USUALLY OUT OF DATE BEFORE IT IS PUBLISHED.
That is exactly right because anyone can create a schedule once a week. The main benefit of a good scheduling system is that it is able to reflect priorities that are always changing while providing you with real-time information. This is what enables you to systematically make smart and fast decisions. Being able to understand cause and effect at high speed immediately differentiates you from your competition.
MY SCHEDULERS KNOW THAT OUR ERP SOFTWARE DOESN’T HELP THEM SCHEDULE, SO THEY HAVE DEVELOPED THEIR OWN HOMEGROWN SOLUTIONS USING EXCEL SPREADSHEETS.
Once again this sounds like a good idea, but it usually isn’t and there is a chapter, titled “Excel, the False Messiah,” that gives a full explanation as to why this is not a good idea. The short answer however is that the illusion that Excel gives you some control is quickly offset by the exorbitant amount of time it takes to keep the schedule current without any of the built in benefits that come with a good scheduling system such as a visual schedule, easy data integration, and the ability to use sequencing rules. If the schedule does not reflect current reality then it is of no use to you.
BECAUSE WE ARE IMPLEMENTING LEAN CONCEPTS MY CONSULTANTS TELL ME THAT WE DON’T NEED A COMPUTER -BASED SCHEDULING SYSTEM.
Replacing complex ERP logic with Kanban and demand-based manual systems is very tempting, but of course it has its limitations. Toyota themselves recognizes the limitations of these techniques in a demand-driven business model. This is because manual systems do not give you the ability to plan around your capacity constraints. This becomes critical once the buffers of time and inventory have been removed from the equation. In most cases an APS system will support and improve your lean initiative.
SCHEDULING SYSTEMS ARE TOO EXPENSIVE.
This one of course is true if you have a bad scheduling system that doesn’t reflect the reality of your world. Good scheduling systems can pay for themselves almost overnight and are capable of adding millions of dollars to your profit every year. If you are in the business of selling capacity, what other tools do you have to manage this process? If you don’t manage this process, you will be tempted to sell your capacity on a first come first served basis, and that is a very good way to lose your key customers.
I CAN IMPLEMENT MY OWN SCHEDULING SYSTEM.
Although there are some out there who can do this, it needs someone with a great deal of knowledge about manufacturing and the software that is being implemented. Ultimately the success of the system depends on your ability to match the capabilities of the software to your business needs. Knowing what works and what doesn’t can save you thousands of dollars. The pay back can be ten or even one-hundred times better when the implementation is done well and the schedule is tightly coupled with your business processes and constraints, so the risk is great.
MY BUSINESS IS DIFFERENT THAN ANYONE ELSE’S.
Yes this is almost certainly true and although the basics and root problems are always the same, the solutions will vary greatly. One of the strengths of a good scheduling system is that it can be easily tailored to meet your needs so you don’t have to change the way you do business to fit the system. The trick is to find someone who has the experience to guide you through the process.
WHAT HAPPENS WHEN MY NEEDS CHANGE AND I HAVE MADE MAJOR MODIFICATIONS? WILL I ORPHAN MYSELF FROM NEWER VERSIONS OF THE SCHEDULING SOFTWARE?
This is really a great question and the answer is that, unlike most ERP systems, the best scheduling systems are designed to be customized just like Excel. This means that upgrades to new versions can be implemented with minimum effort because complex changes can be made without changing the actual core system. If you have selected the right APS system then upgrading to the latest version should be no more difficult than installing a newer version of Excel.
I DON’T WANT TO KEEP DATA IN TWO SYSTEMS.
Of course this is a valid concern and a good scheduling system will have the ability to smoothly integrate the data with your ERP system, your shop floor data collection system and any other system that it shares data with your scheduling data such as your purchasing system.