DIfference between Periodic Lot Size and TDS

[Former Member]

Hello!

Imagine 2 cases:

1. In one material I have a periodic lot size of 3 days, and 0 TDS

2. In other material I have a lot size EX (every day) and 3 days of TDS

What will be the difference in TLB proposal of every morning?

Thank you very much in advance,

Julia

[marianoc · Accepted solution]

Hi Julia,

Could you clarify what is TDS?

Thanks and Regards,

Mariano

[Former Member · Accepted solution]

Hello Mariano,

Thank for paying attention to my question.

TDS is Target Days' Supply.  It is set up in MM02

I hope now is more clear, let me know in other case,

Thank you very much,

Julia

[marianoc · Accepted solution]

Hi Julia,

Target Days' Supply and Lot Size are two different concepts, not related at all.

Lot size (materials plannings)
Key that determines which lot-sizing procedure the system uses within materials planning to calculate the  quantity to be procured or produced.

Safety Days' Supply
In SNP, the safety days' supply specifies the number of workdays over which the 
system has to take into account future demands when planning safety stock. For 
example, if the safety days' supply is three days, the safety stock has to cover 
the demands for the next three workdays.

Let me clarify with one example.

Suppose that your demand is 10 CS per day.

Suppose that your lot size is 3 and your TDS0. In this case, because the TDS is 0, you will buy exactly what you need. So you will buy 30CS for Day1, and then you will buy again 30 CS in Day4 and then in Day7.

Now if your TDS is 3, this means that your safety stock should be 3 days of inventory.. which means 30 CS..  if your lot size is 0, then you will buy as its showed in the following table in green:

The first time you buy in order to build the safety stock.. you buy 40 CS.. and then you just buy 10 CS to keep a Projected stock of 30 CS.

Now if your lot size is 3 days and your TDS is also 3, this is how you will buy:

Hope this clarify your doubt.

Kind Regards,

Mariano

[Former Member · Accepted solution]

Hello Mariano!

Very, very clear. Thank you very much!!