Wow.....embarrassing that the solution has been right in our face for
years and we haven't seen it. I do have a few questions.
We ran a test yesterday and was able to see the due/release dates back up
when lead time was entered for the FG number. However, we also included
lead times for the level 1, 2, 3 items so we experienced excessive back
dating because we used lead time values that exceeded the lead time for
those processes. If we want there to be one day additional backward
scheduling through out each level in the BOM, will MRP default to a one
day value between each level in the BOM or should we enter LT days of 1 at
the level 1, 2, 3, etc. items?
Jeffrey D Holder
Chief Financial Officer
P.O. Box 349 I 160 Commerce Drive I Bay Springs, MS 39422
Phone - 601.764.4121
Date: 07/12/2019 12:00 PM
Subject: BPCS-L Digest, Vol 17, Issue 40
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1. Re: Move/Queue Day exclusion from forecast requirements
date: Fri, 12 Jul 2019 04:34:02 +0000 (UTC)
from: Les Mittman <lmittman@xxxxxxxxxxxxx>
subject: Re: [BPCS-L] Move/Queue Day exclusion from forecast
It appears to me from your explanation that there is something incorrectly
setup with your MRP parameters.If I correctly understand the process that
you described, here is what I would expect should be happening.
1.? A Forecast is created in MPS/MRP from the Customer's EDI transmission.
It appears from what you said that the Start Date and the End Date of the
Forecast are the same value which is the Date on which the Customer wants
you to ship the Order from your Plant.
2.? When MPS/MRP runs, I would expect that a Planned Order for the
Finished Good Item will be created for the Forecast.? The Due Date of the
Planned Order will be the Need Date of the Forecast which is the Start
Date of the Forecast.? In this way, MRP is planning for you to have the
manufacturing process complete by the Ship Date which is the Start Date of
3.? For this F.G. Planned Order, MRP will calculate the Release Date of
the Planned Order using the Lead Time that is defined for the F.G. Item
Number.? It will subtract these Days from the Due Date in order to
determine the Release Date for the Planned Order.? So, if the Lead Time is
2 weeks, then the Planned Order Release Date will be 2 weeks before the
Due Date.? This Release Date is when the S.O. that will be created must
start in order for the F.G. Item to be completed by the Due Date.
4.? For all of the 1st Level BOM Components of the F.G., MRP will set
their Need Dates to be the Day before the F.G. Release Date.? In this way,
MRP will be planning Demands for the Components to be in-house before the
F.G. is to be started.? This Need Date will be the Due Date for the
Components.? Then, MRP will use each Component's Lead Time in order to
determine its Release Date.
5.? If any of the 1st Level BOM Components are themselves manufactured,
then MRP will perform the same process to determine the Release Date/Due
Date for the next lower Level BOM Components.? This process continues
through all BOM Levels.
6.? With the process described above, all of the Item Numbers from F.G.
Item down through all Components will have the correct Planning
Release/Due Dates.? So, if you execute to these Dates, you should be able
to successfully complete the F.G. by the Ship Date.?
7.? When it is time to create the S.O., its Release Date should be the
Planned Order Release Date.? Therefore, the Need Dates of any Components
should still be the MRP Planned Need Dates.? You should not see the S.O.
Need Dates being pushed back as to describe.CAVEAT:? The S.O. Dates should
be close to the MRP Dates if the Elapsed Time of the S.O. (i.e. Setup Time
+ Run Time + Machine Time + Queue Days + Move Days) through the Router is
equal to the MRP Lead Time that you have defined for the F.G. Item.? If
there is a significant difference between Lead Time and Router Time, then
you will see the S.O. Need Dates move relative to the Planned Order Dates.
I suspect that you do not have Lead Time defined for the F.G. Item.? If
this is true, then I would expect the MRP Planned Order Release Date for
the F.G. Item to be the same as the Due Date.? That is, MRP will plan to
have the Components available on the Day that the S.O. is to be completed
which is way too late.? This sounds like what you are experiencing.? Then,
when the S.O. is created, the Need Dates of the Components will be pushed
back because of the Routing Elapsed Time which will be used for the S.O.
So, first thing, please check the F.G. Lead Time.
An additional technique that you could use if you want to push back the
Dates for the Components is to set the Forecast Start Date to be before
the Forecast End Date.? That is, currently the End Date is the Ship Date.?
Set the Start Date to be 2 weeks before the End Date.? Then, MRP will
create the Planned Order to be Due on the Start Date.? HOWEVER, I DO NOT
RECOMMEND this approach.? You really should be using the MRP Lead Time to
properly manage the Requirements. ?
Please let me know if you have any questions.? Feel free to contact me
offline to discuss these issues further.? I am a BPCS/ERP LX Consultant
and I work extensively with MPS/MRP education, training, and consulting.?
I would be happy to assist you further.
On Thursday, July 11, 2019, 8:59:20 AM CDT, jdholder@xxxxxxxxxxx
I'm a user/trainer/liaison for development of BPCS for 20+ years.? We
attempted many times to resolve this issue with no success.? Just
wondering if anybody has seen this issue and been successful in coming to
We received forecast demand from our customers via EDI and is entered into
our BPCS MRP system in an automated process.? When MRP runs and plans
requirements for a forecast order, the requirements have a need date that
is equal to the date the customer requests the shipment.? This does not
allow for receipt of material early enough to allow for processing time.
When the order firms up, we enter an order (ORD500) and shop load the work
orders to produce the order.? When the work orders are created, the
backward scheduling parameters kick in and move the requirement date from
the date the customer want the order shipped back to a date that allows
for the process time represented by the values in Move & Queue days.? For
a product with a two week process time, the act of shop loading the order
(which takes the Move & Queue days into account) changes the need date for
the materials by two weeks.? We commonly firm the order and create the
work orders between two and four weeks before shipment.? This creates a
substantial change in need date close to the end of the life cycle of the
Has anyone experienced this problem?? If so, have you reached a solution
and what was done to resolve the issue?
Jeffrey D Holder
Chief Financial Officer
P.O. Box 349? I 160 Commerce Drive? I Bay Springs, MS 39422
Phone - 601.764.4121
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