[Erp5-dev] Split and defer problem in original ERP5

[Łukasz Nowak]

Hello,

I've managed to have one Sale Packing List from many Sale Orders. I've
written Solver for situation, where there is line with same resource.

Below is scenario which is common in business, but current
implementation of ERP5 cannot solve it (with appropriate solver).

May be such discussion be moved to wiki - so person responsible for it
shall start it there.

Sale Order 18
source = source_section = src
destination = destination_section = dst
start_date = 2010/12/01
stop_date = 2010/12/01
Line 1:
Resource res
Price 100
Quantity 250

Confirm ->

Sale Packing List 31
source = source_section = src
destination = destination_section = dst
start_date = 2010/12/01
stop_date = 2010/12/01
Line 1:
Resource res
Price 100
Quantity 250


Update quantity to 200
Invoke Split and Defer to 2010/12/15 for solve
Generates:

Sale Packing List 32
source = source_section = src
destination = destination_section = dst
start_date = 2010/12/15
stop_date = 2010/12/15
Line 1:
Resource res
Price 100
Quantity 50

Again Sale Packing List 31
Update quantity to 150
Invoke Split and Defer to 2010/12/20 for solve
Generates:

Sale Packing List 33
source = source_section = src
destination = destination_section = dst
start_date = 2010/12/20
stop_date = 2010/12/20
Line 1:
Resource res
Price 100
Quantity 50


Right now SPL-31, SPL-32, SPL-33 are all 'solved' - GREAT!

Go to SPL-32, update quantity to 25. Split and Defer to 2011/01/15 for
solve
Generates:

Sale Packing List 34
source = source_section = src
destination = destination_section = dst
start_date = 2011/01/15
stop_date = 2011/01/15
Line 1:
Resource res
Price 100
Quantity 25

And now it is time for SPL-33. Update its quantity to 25. Split and
Defer to 2011/01/15 for solve.

End of story. SPL-34 will be diverged forever.

Isn't above normal business scenario?

Proposed solutions:
a) write solver which update delivery ratio and allow to update line in
SPL-34 (I made it, I think I may share it)
b) be able to have more than one line with same resource (I do not know
implications)

(a) has defect: unattended SPL update. But it my be solved, that SPLs in
state draft are updated, and if user set its state to confirmed new will
be create on that same date. I do not know implications...

Because of high probability of such scenario (a) or (b) solution IMHO
shall be in default erp5_trade.

Thanks for your attention,
Luke