Thousands of suggested action msgs in planning worksheet

Hi there - I know that my question here is quite general but I’m not sure where to start…

I’m in a manufacturing business running Nav. We run MPS and MRP every Sunday night. On average we get a total of 8366 action messages to work through for the week which is just not practical. On a very similar business running an old BPCS system for the same period we used to get approx 150 messages / week!

This is obviously a symptom of our set-up but what I would like some assistance with is where to start tinkering with this. Below is a summary of the types of action messages we get on a weekly basis. For this week’s plan we altered the dampening and saw a shift in the messages between new and re-schedule. But I’m not sure if that had the desired effect.

I also notice that in looking at an individual material we get conflicting messages every week - order, cancel, reschedule out, bring forward, order again etc.

One parameter I was thinking of changing was the re-order cycles on individual items. Most of these are set as 1W - weekly. I would’ve thought this should be 1M - monthly. Any comments on that?

Also, our MRP is run on top of MPS - the planners do not run MPS, move production plans around and then run MRP. So I guess Nav is planning for unlimited capacity (we don’t have capacity planning in the system) and this might be the cause of so many action messages?

Ref. Order Type Action Message 22/03/2009 30/03/2009 7/04/2009 14/04/2009 20/04/2009 27/04/2009 4/05/2009 Grand Total
Prod. Order New 3,889.00 4,084.00 2,873.00 4,060.00 173.00 2,442.00 1,946.00 19,467.00
Cancel 44.00 25.00 58.00 99.00 14.00 74.00 73.00 387.00
Change Qty. 12.00 28.00 24.00 25.00 1.00 121.00 97.00 308.00
Resched. & Chg. Qty. 103.00 77.00 124.00 142.00 20.00 145.00 98.00 709.00
Reschedule 87.00 86.00 56.00 96.00 16.00 139.00 113.00 593.00
Prod. Order Total 4,135.00 4,300.00 3,135.00 4,422.00 224.00 2,921.00 2,327.00 21,464.00
Purchase New 5,191.00 5,626.00 4,128.00 5,352.00 5,381.00 3,983.00 2,917.00 32,578.00
Cancel 216.00 351.00 376.00 182.00 210.00 325.00 327.00 1,987.00
Change Qty. 41.00 61.00 36.00 55.00 54.00 67.00 133.00 447.00
Resched. & Chg. Qty. 132.00 140.00 136.00 161.00 140.00 172.00 104.00 985.00
Reschedule 25.00 25.00 22.00 34.00 36.00 49.00

Well to start with you have 9,740 action messages. 9080 of these are “new” are you saying this is too many? These are telling you within the parameters set and the dates you need to produce/purchase against 9080 lines - do you actually check all of these? You could reduce these as you said by setting the reorder cycle from 1W to 1M, thus quartering your messages, but probably massively overstocking your warehouse - so this depends upon leadtime, stocking levels and volume.

The other 660 messages are because demand has changed, this is equivalent to your previous 150 messages, but I cannot comment on the structure of your old messages. The cancel just tells you you should not be doing it - but can you actually stop it now? The others are simply quantity and date changes.

My first question would be what is your end date on the run, and does it need to be that far in the future?

I would then advise you analyse the reorder points, the reorder cycles etc. Do you have any order multiples or minimums set as this would probably smooth the order pattern as well.

The unlimited capacity is not causing your messages, but if you move the production plan around this will cascade down through all planned BOM’s and purchases, so in essence when you move the plan you create these reschedule messages yourself.

In my opinion the Planning engine in NAV was designed by some perpetual student, i.e. someone that spent their whole life in schools and has never seeen things like blue sky grass and the ocean.I have installed A LOT of Navision systme, and never once have I seen it comeing even close to doing what any real world user would want. Recently they made an attempt to fix it, but all they did was fix the code without any consideration that they were fixing something that is fundamentally broken.

Can anyone honestly say that a sane normal person would consider functionality that says "Oh no this purchase order for 1,000 items will be too late to meet the dead line, so please call up your vendor, and tell them to cancel the order (even though the goods are probably allready on the truck), then change the date so that the truck leaves three days earlier in the past.

Without owning a time machine, there is no possibility for the engine to work. And unfortunately none of my clients are Time Lords.

Then stupid things like you order 10,000 items, needed 14 days in the future, but it then for some reasons will tell you to split the order and ship 9,990 of the items normally, but 10 should be delayed and shipped a day later. Did the person designing this every hear about freight costs and the fact that the cost of changing the order is more than the cost of carrying 10 items for a couple of days.

The only situation I can ever see NAV planning working is where every item has a very high unit value, say more than a days salary for the purchaser and order quantites are low. In which case the cost of managing the inventory is less than the carrying cost of inventory. In those cases, though volumes are so low and values so high, that a manual soultion is better.

The summary of all this is that planning is allways a negative ROI, in that it cost more to use it than the value it gives to the client.

Microsoft should not make any attempt to fix this. The whole code should be deleted and started forom scratch, as it is its a total embarassment to an other wise great product.

I do not disagree with anything stated, but I was working on the assumption it could not be completely re-written. [:D]

Hi guys - thanks for your views. I didn’t think the planning engine was very smart but just thought it was our set up… From your views it seems that we just need to make the best of it and try to manage around this.

To answer your questions Adam:

I have a team of four people purchasing off the plan but they struggle to review all the messages every week. We actually only review the purchase messages where the start date is less than two weeks in advance and back - so for this week we are reviewing all messages with a start date of 22nd May and back. There are quite a few messages with a start date prior to today because there are prod messages prior to today and we have ignored some purchase messages.

The main issue we have now is a lack of confidence in the planning worksheet results. When I go through individual lines I struggle to see why we need to purchase something - reviewing safety stocks, sales orders, forecast etc etc. And because it tells us to constantly do stupid things (as per Davids post) we end up not being sure which messages to accept and which to ignore.

We use lot for lot reordering policy so no re-order points / quantities set. We don’t set safety stocks on raw / packing materials, generally have a 1W re-order cycle and set the min order qty = to order multiple.

I’m not sure that making the reorder cycle 1M would massively overstock us because it appears that we are currently buying in four lots of a material in a month and only use the total qty at the end of the month. So if we had bought the total month’s worth in one go it would be the same qty of material but come in once and then go intoproduction. Right now I get four deliveries which sit around until everything is here. There does not seem to be a link between raw and packing order multiples and production multiples.

We do run the plan quite far out because my other gripe is that I cannot get a decent forecast out of the system to give to suppliers. But we restrict the number of messages to review by only looking out two weeks as mentioned above.

Thanks for your advice

I would suggest as a starting point that you set the reorder cycle to 1M, if it really makes no difference it will quarter the action messages in a month if we are still considering “New” as a message.

If you are reviewing the “New” messages then this would be my starting point. You have to have confidence in what it is telling you is correct to enable you to simply action teh “New” messages and concentrate on the other smaller number of messages. In your old system you reviewed 150 but it would still have given you 5000 make/buy actions which I presume you accepted out of understanding and confidence. I would advise that you get your partner to come in and sit with you and go through the investigation of the action messages. You need to build this confidence up to enable you to accept the “New” messages without review - if the settings are correct it is simply suggesting supply to meet your demand.

Also why did you go with the lot-for-lot with no reorder point? There are many issues with different policies and I was just wondering why you chose this one.

No you missunderstood. The planning engine is very smart, but tooooo smart. It reacts to everything. Its like it was written by someone that spent their entire life in university and still lives at home with their mother. The real world just is not like this.

I believe they have moved out and live in a flat by the railway station now [:D]

Hi there,

Thanks again for yout time and replies.

I’ll test the suggestion of changing some SKUs to 1M and see what messages I get for them next week.

I’m not sure why the lot-for-lot was chosen initially. The business has been using it for some years but no one has questioned the output and why we’re constantly having issues with materials arriving on time - and why Nav seems to be suggesting we place an order for which we can find no logical explanation.

It is the ones that lack a logical explanation that worry me - you should be able to find the demand for everything, otherwise something is wrong - I presume you have no modifications?

I’ve worked within a business that had similar issues… they had something like 10,000 stocked items including multi-level assemblies etc… and were swamped with action messages whenever they ran MRP…

They eventually managed to considerably reduce these messages by :

  • reducing the levels within their BOMs… each level within a BOM generated a production order whenever there was demand for any of the items associated with a higher BOM level. Use of phantom items where possible helped a great deal.
  • Changing their internal processes for managing stock and sales order processing - moving to a manual flushing environment (from a backflushing one) helped enormously as did changing their sales order entry /amendment processes - a lot of time, they were changing requested delivery dates and items on open sales order lines which then drove a wave of changed demand back through MRP
  • amending the reorder cycle (as mentioned by previous posters)

Hope that helps [:)]

Hi Tim and Adam,

Thanks again for your advice. I did some testing over the weekend with the reorder cycles on some categories. This week we have a lot less noise in the messages - fewer change requests - which makes it easier to focus on and action the messages.

I’m doing some further testing now on min order quantities etc to make sure that we’re ordering in line with our production and forecast requirements.

Thanks for your other suggestions Tim - I’ll look into those as well.