Transit time and Transportation lead time is taken from or maintained in Route
Loading time and pick/pack time comes from shipping point
You need to have clarity on backward scheduling and forward scheduling
For example you are creating a sales order today 15.02.2009 and the requested delivery date is 25.02.2009 from the customer side
Transit time is 2 Days
Transportation planning time is 2 days
Loading time is 1 day
Pick/pack time is 1 day
Consider these settings
Now backward calculation System does a backward calculation first
25.02.2009 (requested delivery date) — 2 days (transit days) — 1 day (loading time) — 2 days (transportation planning time) = that is on 20.02.2009 there should be enough stocks in the unrestricted stocks and system checks stocks for this day or date ,that is 20.02.2009 ,whether the stock is available enough
This date 20.02.2009 becomes the material available date
Note Transportation planning time and Pick/pack time will run parallely and the highest of these two is considered for delivery scheduling so in our case Transportation planning time is 2 days that is the highest and hence it is taken for calculation and not pick /pack time
If the system finds enough stocks on 20.02.2009 (that means it performs a availability check for 20.02.2009 depending on OVZ9 settings) that is material available date then it confirms schedule lines for that order this is backward
Same example order is registered today 15.02.2009 and if the customer wants stocks on 17.02.2009
This means 17.02.2009-2 days (transit days)-1 day(loading time)-2 days (transportation planning time) = 12.02.2009
The order registered date is 15.02.2009and the material availablity date is past 12.02.2009 or material available date goes to past.
This is illogical
This means backward is failing here and now forward calculation takes place
Forward calculation
If you have enough stocks today 15.02.2009 + 2 days transportation planning time+ 1 day loading time+2 days transit time = 20.02.2009
This means that is on 20.02.2009 the stocks can be confirmed for this order as against a requested delivery date of 17.02.2009
In forward the system will give 2 schedule lines first that is requested delivery date that is 17.02.2009(in our case) with ZERO qty and the second date as 20.02.2009 with full qty
In backward you will find only one date in the schedule lines which is the same as requested delivery date that is 25.02.2009 in our case
Hope i made things little bit clear to you
Transit and transportation planning will come from route if route is maintained other wise it is taken as 0 days
Loading and pick pack time will be maintained in shipping point if not maintained also then it is taken as 0 days (in enterprise structure logistic execution and your shipping point details it is maintained)