Re: Starting up the MRP module -- BPCS-L

Rob

I'm on V4.05 CD Rel-2 modified.  We run MRP MPS CAP, plus so heavily
modified DRP that it does not resemble BPCS DRP.
The major gotchas, in my opinion, are embodied in a mass of end users who
have a mental picture of how MRP operates that can be totally at odds with
how it really operates, and thus they do things that invite trouble for the
company, and so the
# 1 most important thing for your company is to get education in BPCS
Planning for all the people who will be contributing input to it,
especially top management.

Do you have a sales department that wants to accept any order from any
customer with any promise dates irrespective of company ability to fill
that order?  That's a good department to have if they can get the business,
and sustain the volume.

Our bottlenecks are lead times on some raw materials, and fixed setup times
irrespective of quantity.  Another company's bottleneck might be in
capacity planning.  You need to know what your bottlenecks are, and how you
can compensate for them.

How accurate and up-to-date is your BOM routings engineering inventory
production reporting?
MRP can only plan based on the veracity of the data supplied to it.

Do your people know what your real lead times are, and is this reflected
both in the BPCS data and in acceptance of customer orders.

This is another potential gotcha.
MRP does not plan stuff that is past due when first entered into the system.
Suppose the lead time on some vendor parts is 60 days, and suppose a
customer order is entered that has to be delivered in 10 days.
What will happen is that you will run out of that vendor part, because MRP
ignores the part of the requirements that are past due, and just plans what
is inside the lead times.
MRP does this because BPCS assumes your people know what they are doing
(bad assumption) by entering requirements that violate lead time, and that
someone will manually be planning what to do about such exceptions.

To a certain extent you can off set the misconceptions crowd by injecting
heavy safety stock and working with various fields of MRP planning, but
management might not want a lot of money tied up in safety stock buffer
against bad information in your system.

What you can do, is make your MRP planning date an absurdly distant time in
the past and run your MRP as if your factory had a time machine and lead
times were irrelevant.
MRP will then schedule stuff using your ficticious time machine, and all
the past due lead time violations will be in your plans, and you can go
from there.

I'm on V4.05CD.  We've never implemented MRP, MPS, etc., etc.  We are using
SFC, PUR, INV, ORD in a 1960's type of computing environment and I've been
charged with starting MRP up and using it.  We manufacture carbide cutting
tools - buy a piece, grind on it, maybe do an outside service to it, inspect
and shelve (or ship) it.

We have some extremely knowledgeable manufacturing guys who can interpret
MRP terminology and, with my assistance, convert it to BPCS-speak.  My
question is are there any unexpected gotchas in MRP?  Will I come in to work
one morning to be greeted by irate users, upset management and the always
dreaded pink slip?

-
Al Macintyre (macwheel99@sigecom.net via Eudora)
Al's diary http://radio.weblogs.com/0107846/
Cure cancer. http://members.ud.com/about/