Supply Chain Management with APO

326 16 Sales in a Make-to-Order Environment
• ATP with Allocations
The ATP check against allocations in general is explained in section 7.5.
In this case the idea is to use the allocation quantities as aggregated capacities.
This is of course only possible if the production structure allows to
define a capacity per product group. It is possible to consider the lead time
by combining the allocation check with a product check and using the
check horizon for the product check.
• Combined Sales and Production Planning
The other two solutions – CTP and ML-ATP – both trigger the creation of
a planned order by the ATP check. This means that sales is performing
production planning tasks (in the background). The combination of sales
and production planning in the ATP check does have impacts on the production
side, mainly for the functions for production planning in SAP
APO. These are described in the limitations for CTP resp. ML-ATP.
From a business process side the no major changes regarding the responsibilities
and the exception handling are expected. The biggest hurdle
is to get the planners’ acceptance to pass the control about the planned order
creation to sales.
• CTP for Make-to-Stock
When CTP or ML-ATP is used, this should be the only source for production
planning. It is however possible to apply CTP in a make-to-stock scenario
if a part of the demand is planned for with independent requirements.
This increases the complexity of the solution and has to be tested very
thoroughly.
• Scheduling
For both scenarios – CTP and ML-ATP – a subsequent scheduling step is
necessary. Even though CTP performs a finite scheduling (either on detailed
level or using a bucket capacity), the production sequence will be
defined by the more or less arbitrary sequence of the sales orders and will
most probably not meet the requirements for a production plan.
• Time-Continuous CTP vs. Bucket-Oriented CTP
There are two options how to perform the CTP check, one is the check
based on a detailed finite scheduling, and the other one is to check the capacity
based on a finite bucket capacity, which does not regard the detailed
sequence of the orders within the bucket. We recommend to prefer the
bucket-oriented CTP to the time-continuous CTP whenever possible.