Purpose of PPDS optimization

[Former Member]

Hi,  

     Can someone explain to me the purpose of the PPDS optimizer as compared to the heuristics. Both are used for finite scheduling. I know its to optimize a business objective depending upon business need (setup, makespan etc). I have read the online help a few times but I dont clearly understand why is optimizer needed if the DS heuristics and functions do the finite scheduling. All of them consider the time and pegging reletionships within orders and across orders. So why do you need both the optimizer and the heurisitcs? What does the optimizer do which the heuristic does not do and vice versa? If the scheduling heuristic has determined production dates finitely then would the optimizer change those dates again ? Please do not provide me the link of the online help.

Thanks

[Former Member]

GS,

You are assuming that each planning problem has only one way to be scheduled.

In general, heuristics will produce a planning solution.  If the heuristic is considering finite resources, it can be made to produce a finite solution, which is probably feasible (can be executed as it stands), unlike MRP which by itself does not consider feasibility.  Usually, heuristics consider single fixed solutions for each discrete planning problem, and come up with a single solution for each of these problems.

Optimizers in general become valuable when there are multiple ways to execute a production plan.  For instance, there may be 5 production versions for a manufactured material, each of which consumes different resource capacities, with different rates of consumption, and with different BOMs.  There also may be 5 different sources for a purchased material, each of which has its own quality level, delivery time, and price.  With an optimizer, you can set the optimizer run to find the SINGLE BEST integrated overall solution.  It can be made to consider all different permutations and combinations of the supply chain. Common factors to optimize are cost (e.g. lowest overall cost), and service (e.g. highest overall service).  In general, an optimizer will consider each discrete planning problem, and will iteratively try each possible solution until it finds the BEST solution. 

So, optimizers not only produce FEASIBLE solutions, they find the BEST FEASIBLE solution when there are multiple options.  This is the great advantage of optimizers over heuristics.

Best Regards,

DB49

[Former Member]

Hi! I need to know if it is possible to optimize minimizing cost and maximizing incomes at the same time.

I mean, is possible to configure the price of the product to be considered during the optimization?

If there are two materials with the same cost of production but one of them is more profitable, I would prefer the optimizer to priorize it. In case it is not possible, has PP/DS some Evaluating Report that compares two different solutions of the optimizer, in terms of profitability?

Sorry my English is not good, I am studying

Best Regards, Natacha

[Former Member]

so is optimizer mandatory....it does not seem to be manadatory to be run after the detailed scheduling run. Also in cases where is it run does it land up changing the scheduled dates determined earlier by the DS run ?

[Former Member]

GS,

No, optimizer is not mandatory.  Many companies run PP or PP/DS without optimizer.

When it does run, it will almost always change dates determined by any previous heuristic (PP or DS) unless the orders are fixed..

Best Regards,

DB49