MRP issue

Tommy

hi everybody,
does anyone knows when the Planning Worksheets will suggest cancel the purchase order or reschedule/ change quantity?
what parameter can influence the purchase supply?

i got the results that some is cancel, other is reschedule, but i don't want the purchase order be canceled. is it possible?

thanks

santoshmkcet

hey tommy,

there is nothing of the sort that the system will suggest to cancell a purchase order!!!

it will suggest only a warning that there is excess qty, but not to cancel, the decision is solely ours!!! got it?

santosh

cernst

On the item card tab planning you have a field Reorder Cycle. If there has been made changes in time that is greater then the time in this field the system suggest cancelation of existing order and an other line with a new order. If changes in time is within the time in Reorder Cycle then you get a line with "Reschedule".

Tommy

hi noname, thanks for your reply.

i have tried that Reorder Cycle, sometimes the field is unuseless for some item. even the Reorder Cycle has been 10Y, the system still suggest me to cancel the purchase order.

especially when running the MRP with lots of requirementthis.

vanrofi

It is the planning flexibility. This is default placed on unlimited (see Requisition Line and Purcahse Line.

You should make default on requisition Line and Purchase Line on Never or none and problem solved...

Stupid that Microsoft does not make it a setup field : default planning flexibility in Purchase setup...this way the user decides it's flecibility.

The flexibilitity is not wide enough....it replans PO that have been released, printed,...incredible fixed feature, if I may say so?

cernst

When you get message cancel then I suppose you also get a message new to create a new purchase order to meet the demand?
What reordering policy are you using? if you use "Fixed Reorder Qty." then this should work.
Try to run the planning worksheet for only one item and try some scenarios for example create a sales order and run planning worksheet to create a prurchase order then change shipment date to something within reordering cycle and run planning worksheet again the you should get message reschedule. Then change shipment date to something greater the reordering cycle then run planning worksheet again you should get a message cancel and also a message new.

cernst

Felt i needed to comment the use of planning flexibility. The intended use of planning flexibility is to override the suggested quantity or the suggested date. For example if you get a line suggesting 100 pcs and you this perticular time want to buy 150 pcs then you change planning flexibility to none this way you don't get an action message to change quantity next time you run planning- or requisition worksheet. This only works when you buy/produce more then suggested quantity or you buy/produce it earlier the the suggested date.

If you always set planning flexibility to none then I think you are in trouble. OK you won't get as much action messages but that means that you'll miss changes made in demand. For example if you create a purchase order to meet a sales order and then the customer cancels the sales order then the planner/purchaser won't get any signal that the purchase order should be cancled.

With the right setup the MRP works fine, this is nothing microsoft has invented and most of the time it's nothing wrong within NAV the problem is that MRP is complex and with wrong setup and mostly lack of understanding of MRP then it really can go wrong.

vanrofi

apparently I was not really clear, Mr or Mrs NoName. I know that MRP works only fine with right setup. I was only refering the default setting of the planning flexibility in Purchase and requisition Line. As user you cannot define the default being None. The setup could be wider in a sense that you can define the level of flexibility in relation to 'let's say' the status of the purchase order. - read - planning flexible until PO has status released?

Being critical does not mean lack of understanding and therefor really go wrong...pls. be carefull with fast and easy conclusions. (no hard feelings 8-[ )

Tommy

Thanks for your replies vanrofi and noname.

The planning flexibility I tried but maybe it's not usefule for my case.
the system ignore the quantity with planning flexibility set to none and this result is not what I need.

Yes, when I got the cancel suggestion I also got the create a new suggestion for purchase order. parameters i using are below
Reordering Policy: Lot-for-Lot (including inventory)
Reorder Cycle: 10Y (for all item)
But the Navision still suggest cancel then create new for some Items, reschedule or change quantity for other Items and all Item's parameter is same.

Is there another parapeter can influence the MRP?

cernst

It seems to me that Reordering Policy L4L maybe shouldn't be used. If you read the help regarding Reordering Policy then it says " The program generates an order proposal with a quantity that meets the sum of the requirements that come due within the reorder cycle". To use 10Y as a reorder cycle is something you shouldn't do instead L4L is oftened used with a weekly reorder cyclce 1W in order to look at the need week for week. If this isn't what you want you should try to use Fixed reorder qty as Reordering Policy then you should have the action messages that you want.