Scheduling planned production orders in master planning.

This is (hopefully) first in the series of articles to help you look inside the master planning, to see how it really works, to understand the code.

Ever wondered why some planned production orders are delayed when there is enough capacity?

We can easily reproduce this problem in demo database.

Use a new system with demo data
Create Working times for 24Hours and STD
Reset and delete all the production orders
Run a complete master plan and make sure no planned orders are generated and there are no errors.
Go to P-2000/B, setup -> Item Coverage and set the coverage period to requirement
For the same item go to the route and delete operation 20 and 30. For operation 10 set work center to S-Punch-1. Run time: 48, setup time: 0, Process qty: 200, Next operation: 0
Go to machine S-Punch-1 and set operations scheduling % to 100%, enable finite capacity, change calendar to 24Hours.
Also run this job to delete capacity reservations just in case

static void Job12(Args _args)

{

WrkCtrCapRes wrkCtrCapRes;

;

delete_from wrkCtrCapRes;

}

Now create 2 production orders for P-2000/B, delivery date 2 months from today. Quantity 200.
Now run complete master scheduling.

Whoops! One production order for P-2000/B is delayed even if we have enough capacity before the delivery date. On my system the sales line delivery date is 31^st of July and there is a lot of capacity available for the whole month of July still the planned production order is delayed, why?

Now go to plan MP-1 and on General tab enable Finite capacity.
Now run complete master scheduling again.

Wow! Now the production orders are scheduled correctly as expected. Of course there is now an action message but that is the subject of another discussion.

So what is happening really?

I will post answer in the coming 2-3 days. If you can figure out what is happening and send me an email then (if you wish ) I will publish your name along with your company name on the website.

Think!

*****************************************************************************************************

18th June 2006

No correct answers. What is happening is as follows:

Axapta schedules a production order in coverag. This will in turn create a requirment for the raw materials. During futures all capacity reservations are deleted and all planned production orders are scheduled forward from the raw material date.

In the above example the raw material requirement was created on 29th July (requirement is for 31st July and run time is 48 hours) hence in futures the planned orders got scheduled from 29th July onwards. Now since we are running futures with finite capacity, one of the production orders is getting scheduled correctly however the other one is getting delayed even though we have enough capacity before 29th July.

However, running coverage and futures both with finite capacity is a big time performance hit. However if performance is not a problem for your client then please do run coverage and futures on finite basis to get better scheduling results.

Send mail to harry@systomatics.com with questions or comments about this web site.

Disclaimer: I am working with Microsoft Business Solutions. The code on this site may or may not be related to my official duties with Microsoft. I do not claim in any expertise in modules represented on this website. Essentially there is just one person doing functional specifications (in head), design specifications (in head), coding and some testing. There is no way the project on this site will be free of bugs. The projects are intended as guidelines and may god help you if you decide to implement the projects without making any changes. If you implement any project resulting into data corruption or anything like that then do not even think of suing me because a. I have already warned you and b. I don't have any money. I may or may not respond to your emails about supporting the project. I may or may not upgrade the projects to the next service pack / version.