SNP optimizer performance

[Former Member]

Hello everyone!

    We use a SNP profile with strict prioritization settings (tab “Solution Methods”, group “Priority Decomposition”) for prioritization demand by types. It works perfectly from functional perspective, but as for performance it takes 9 hours in comparison to cost-based prioritization which takes just an hour.

     Could you please give advice how to improve the performance of the optimizer run? And how to evaluate whether it is a performance issue or the system works just fine?

     Here some statistics: 

No. of Demands 1.648

No. of Periods 17

No. of Location Products 15.345

No. of Products 6.221

No. of Locations 24

No. of Resources 65

No. of Prod.-Spec. Transportation Lanes       11.903

Number of PPMs/PDS 6.521

Details About Internal Model of Optimizer

No. of Variables 270692174

No. of Discrete Variables 0

No. of Discrete PPMs/PDS 0

No. of Discrete Product-Spec. Transportati         0

No. of Constraints 127426101

Time Decomp. (No. of Periods) 0

Product Decomposition (%) 0

Memory consumption 1.913.776 kb

Thanks in advance.

[former_member584840 · Accepted solution]

We did some SNP Optimizer prototyping a year or 2 back, before changing tack to a different way.

some early jobs.

8549 MB 4 hours

Then from memory, we ramped up the memory to about 24 GB to be able to handle our model.

That was using DISCRETE OPTIMIZATION though. TO be able to download blocks. LINEAR was a lot less memory. ie in the selected method above all the tabs in the profile.

[Former Member · Accepted solution]

Hello John!

     We use linear optimization only, so the memory is not the issue at the moment I guess.

Best Regards,

Vladimir.

[former_member329476]

Hi Vladimir,

Can you please shed some light how you are doing this : "prioritization demand by types"?

How many demand types do you have?

Are all demands within each demand type have the same priority?

How many LP solve run do you have?

Kind Regards,

Omar

[Former Member]

Hello Omar.

     Optimizer can consider 3 types of demand, they are assigned to ATP categories: BM, FC and FA respectively. The only settings in the optimizer profile is "strict prioritization".

     Within each type the demand has the same priority and the solution is found with a single run.

Best regards,

Vladimir.

[former_member329476]

Thanks Vladimir?

What are the "Details About Internal Model of Optimizer" and "Memory consumption" in case of "cost-based optimization"?

Kind Regards,

Omar

[former_member182502]

Dear Vladimir,

I understood that you don't want to use Cost base optimization but use "Strict prioritization" option. I would suggest to you to use Time Decomposition (3 Buckets) option. This is suitable only if you are looking for an accurate plan in the short term/medium term and ready to compromise the quality of result for the few buckets in the end.

Example since you have 17 buckets the plan will be same for first 12-14 buckets. Last buckets may not have the same accuracy. I have used Time Decomposition in the past and the results were satisfactory.

Thanks and Regards,

Gajanan Patki

[satish_waghmare3]

Hi Vladimir

Please do specify reasonable Maximum Runtime in Solution Method Tab in Optimizer Profile.  I have experience with similar issue when Optimizer user to take close to 7-8 hours to complete without doing much(feasible solution not optimum) for Product deco iteration which used to run for longest amount of time.

Once we reduced the Max runtime from 720 mins to 180 mins, we were able to achieve quicker completion of optimizer and without much impact on quality of solution.

We tracked Service Levels, Number of fulfilled and Unfulfilled demands, Number of Product Deco iterations, Number Optimal solutions and Number of feasible solution by using Optimizer log.(/SAPAPO/SNPOPLOG).  If you decide to go with this option, please do track these key indicators for 8-10 runs to know the impact of this change.

Hope this will help

Thank you

Satish Waghmare

[Former Member]

Hello Satish!

     Thanks a lot! We didn't look at this option cause the provided solution can be not optimal. But we didn't check the quality either with reduced duration.

Best regards,

Vladimir