Safety Days Supply is not considered by PPDS planning heuristic

[Former Member]

Hi,

For Product/Location in Product Master we have

maintained Safety Stock Method:SM and Safety Days' Supply = 10. In

Model Version Management we have maintained for feild ''Take Safety

Stock into Account''= 2.

When we are running PPDS Heuristic Intereatively in /sapapo/rrp3,

system is replenishing only demand qty, not considering any safety

stock for the period.

Need your suggestation please....

thanks,

Priya

[Former Member]

Hi Priya,

In PP/DS, only procurement planning heuristics take the safety days' supply into account. Procurement planning heuristics use the safety days' supply as a safety time. A safety time ensures that a requirement is not fulfilled on the exact date and time required, but at an earlier point in time. This means that appropriately early receipts should be used or generated during planning.

A procurement planning heuristic considers the safety time by subtracting the safety time from every requirements date and time at the start of a planning process. This means that it moves the requirements date and time to a point in time that is appropriately earlier. The net requirements calculation is made on the basis of the requirements date and time that was brought forward. When recreating receipt elements for an unfulfilled requirement, the requirements date that has been brought forward is the desired availability date.

You specify the safety days' supply as a number of workdays, where it is possible to have up to two decimal places and a workday equals 24 working hours. For example, if you specify 0.5, the safety time is 12 hours. The system uses the location's production calendar to determine the working times.

Normally, for days of supply SZ method will be used alongwith entry to be maintained under safety days of supply and for fixed value of safety stock, SB method will be used having value maintained under safety stock field.

Regards

R. Senthil Mareeswaran.

[Former Member]

Hi ,

Can any one give some thoughts about Safety Stock Planning in PPDS??? If you have a Fixed number , that you can maintain in the Product master in Safety Stock feild and system will plan that extra. Is there any other option like maintaining no of days of future demand etc?? How it can be acheived??

[Former Member]

Hi Nitin,

Yes, i have maintained SZ as Safety Stock Method. and have seen if we put Safety Days Supply in Product Master as 10 days, then system is preponing the receipt by that many days. Thats what you have explained also.

But i want , Safety Stock should be next 10 days demand, that's what SNP does. I tried to enter the same in Target Days Supply, with Target Stock Level Method as Blank, 4,5,6 . But in none of the cases system is considering Safety Stock for planning.

Can any one throw some light Safety Stock planning in PPDS. How we can model ''No of days'' safety stock in PPDS???

[nitin_thatte]

Hi Priya,

I don't think you can make PPDS work like this. At the most, you can try maintaining a daily lot size with no of periods as 10 days. It will create a receipt big enough to cover 10 days requirement but it will not create daily receipts such that on no day the stock coverage is less than 10 days.

Edited by: Nitin Thatte on Apr 20, 2009 2:03 PM

[nitin_thatte]

Hi Priya,

I hope you have also maintained SZ in safety stock method field.

In PPDS safety days supply is interpreted in a different way. It means that the receipt is advanced by 10 days during planning. That means if the requirement is on 30th April, the planned order will be created with 20th April as receipt date.

In SNP it is interpreted as covering next 10 days of visible demand. If you want to use this safety days supply in this way, try putting the figure in target days supply.

Hope this answers your question.

Nitin Thatte

Edited by: Nitin Thatte on Apr 19, 2009 9:29 AM

[Former Member]

what is the target stock level (right above the safety stock method)

make sure your horizons allow for the coverage.