Book Reviews

JIT Forecasting And Master Scheduling:
Not An Oxymoron

By J. David Viale

Reviewed by Steve Buchwald, CIRM

The book is part of the fifty-minute series and as such is easy and quick reading, containing only 123 pages. According to the author, the purposes of this book are to:

1. Explain the techniques and advantages of long term planning;

2. present a just-in-time forecasting model; and

3. explain how to use forecasting tools.

As far as goals 1 & 3, it is a great tool for use in learning the basics of forecasting and master scheduling. I believe we can assign this book to our students who are taking our basics course. However, as far as #2, there is nothing new here and therefore I am confused on why the author thought he had addressed a JIT forecasting model. If his idea was to present an argument for the need of forecasting and master planning in a JIT environment then he is indeed correct and has presented the correct data. Nonetheless, to treat the subject as if it is a new area is confusing to me and I suspect it will be to others who read the book.
The book is separated into five modules as discussed below. Module one discusses today's key competitive challenges and list what the author refers to as industry's top seven competitive issues, with the top issue being improving forecasting accuracy, which leads to a reduction of inventory. As we will see later, this must be the basis for the author's claim that he has uncovered a new subject area. The second module is on long term planning, which the author refers to as the keys to JIT forecasting and master planning.

As I said earlier, I'm not sure why the author addresses the subject of "JIT forecasting and master planning": forecasting and master planning under any name is still forecasting and master planning. However, on page #18 he did tie back to the module one #1 challenge when he listed the implementation of the JIT forecasting and master scheduling objectives to reduce the forecast error and inventory as being the last of 8 details the manufacturing strategy must address.

But I'm still confused: does the author think that reducing forecast error and inventory isn't an item that needs addressing in a non JIT environment? As I said earlier the author should have addressed this as an argument for the need of forecasting and master planning in a JIT environment, not as a new subject area.
Module three discusses the JIT forecasting model. Here, the author lists the two objectives of JIT forecasting as shipping on time and replacing inventory with information. Again, these sound like fine objectives for any forecasting environment. He ends the module with the five steps to a JIT forecasting model, which once again are great steps for constructing any forecasting model. Module four deals with the JIT forecasting tools. Here he discusses the normal forecasting items such as seasonality, moving average, weighted moving average, standard deviation and mean absolute deviation, to mention just a few.

The fifth and last module deals with JIT master scheduling. Yes, here he discusses MPS and MRP, items that are at the heart of any master-scheduling environment. At the risk of being redundant let me say once again, the reader would have been better served if the author had addressed the subject of some mistaken ideas about the JIT environment not as a new subject area. Let's not forget that some JIT proponents still mistakenly say that forecasting and master planning, more specifically MPS and MRP, are not needed in a JIT environment.

Please don't get the wrong idea. I think the message is a good message. I am only concerned with the confusion that is created by trying to present this as a new subject area. I further think that the book is designed & constructed very well. Each module begins with a discussion of the learning objectives for that module. Then at the end of each module there are ample exercises and activities for the student to test his comprehension of the subject matter. In addition there is room at the back of the book for the student to make notes as he goes through the book. Finally, there is a comprehensive assessment at the end of the book, which consists of 25 questions, along with an answer key, dealing with the three goals of the book.

I invite you to share your comments with me. You can contact me at casperb@earthlink.net. Until then let me say good reading.