MRP: Item Substitution During Message Review

dkontney

Member
Hello,

We have several groups of items that the only difference is the length of the item, so when a B or O message is generated I need a way for the planners to be able to substitute a longer size for the shorter item that the message was generated for rather than placing a new order. I do not want to update the work order parts list or BOMs.

I tried using a seperate forecast type to record the additional demand on the longer size as a positive forecast and then use a negative forecast for the shorter item in an attempt to create additional supply. MRP completely ignored the negative forecast. I could not find any processing options on R3482 / R3483 to allow negative values in the Forecast / MPS row or to be taken into account when determining planned orders.

We are a make to order manufacturing plant using planning BOMs to generate future component demand along with seperate forecasts for items sold as product support or service parts. The parts I'm working with have a 3 month lead-time, with our typical lead-time to our customers of 2-3 weeks.

Actual substitution / decision is made during manufacturing and not upfront during work order release. They keep using the shorter piece until it is used up, then switch to using the next larger size. We have no way to predict upfront which order will use larger size.

I'm looking for a way / process for the planners to identify this substitution for MRP / Ordering purposes only. Method would need to survive future MRP runs. Wanted to use forecasting method detailed above because we use weekly forecast buckets which would force planner to review their substituion on a weekly basis as the forecast would drop out as time passed. Any suggestions would be greatly appreciated.

Running R3483 on E1 9.0.

Thanks,

Dave
 
Dave,

not sure if the below applies to your situation but I'll throw it out anyway.

One of our Mfg Products is a "Graphite Ring" that is sold in multiple item numbers / sizes based on diameter (12", 10" 8", ...).

The rings are "cut" from a solid round of raw material whose diameter shrinks by a couple inches as each size of material is cut from it. A round that started as 12" can produce 10 12" rings after which it is a 10" round (with a new item number). This is shown as a "by-product" or "Core Return" on the Ring's BOM. A 12" round may be shown as a component with a positive qty and a 10" round will apear also on the BOM with a corresponding negative qty.

Work Orders in effect become suppliers of the raw material rounds (in smaller diameters).

MRP sees this in its planning as additional supply and adjusts orders correspondingly.

So, if the cut remnants of your longer items become one of the sources for your shorter items this may help for more accurate planning / inventory levels and help to minimize the shortages you're seeing of the shorter items.

Our Planners use a custom report (see attachment) that combines Supply, Demand, Forecast, and these Core Returns to fine tune Supply Orders for these types of materials.

FYI we require whoever issues parts to the work order to accurately record which size is used as we sometimes do substitutions as well. Improving our planning via the above described methods has minimized this however.

Not what you were asking for but maybe of some help?
 

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Larry,

When we use a larger size, we're consuming it in it's entirety versus producing a co / by product as in your case. For example, instead of using a 8' raw panel a 9' panel will be used. The drop off incurred (1') by using the 9' would be 100% scrap and unusable to us.

We just started using MRP planning within JDE and primarily our production staff requisitions materials based on visual checking of bins and input from future work orders. Because of this we print and release all of our work orders straight from order entry to manufacturing regardless of the order entry date or required date to provide visibility of needed parts. One of the goals of MRP is to replace the production requisition so we can release WO's on an as needed basis rather than way out in the future as we currently do. This is why I'm looking for a solution that does not encorporate work order parts list or BOMs.

Work orders are just a part of the problem. I'm also dealing with planning BOMs which produces approximately 95% of the component demand past 3 weeks.

Thank you for your input!
 
Hi,

I never come accross this one. But a suggestion. Why dont you use OPC - Period's of supply with OPV-20 days are something. So that, you can get a net requirement demand for the period.

Cheers, Aleem
 
Aleem,

I'm already using Period's of supply with a value of 21 days. Didn't include in my original post.

With component lead-time being 3 months, trying to plan what the actual demand will be is prone to error when we provide 2-3 week lead-time to customers. Error is mitigated by the ability of using larger sizes in it's place.

Having difficulty finding a way to tell MRP that we have the shortage covered to prevent B & E messages.

I've kicked around using forecasts, maintaining a fake WO to use the WO parts list and inventory methods such as netable locations. Forecast method did not work and inventory manipulation is not partical for many reasons. Playing with WO method today.

Thank you for your suggestion!
 
Hello Larry,

I took your suggestion and am using co / by products to handle this, however MRP is not picking up the supply from the co / by product. S&D inquiry (P4021) shows the supply, but not MRP. Both P4021 and MRP are using the same supply & demand inclusion rules.

Are you running MRP and does it pick up the supply in your situation? Any thoughts on why MRP is not picking this up?
 
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