Period End closing - Product cost by order

Dear Expert,

Good Evening,

I need your advice on below point.

I want to do the period end closing “product cost by order”. So I have to complete below step.

1. Overhead calculation CO43/KGI2 (Here I skip Actual activity calculation and revaluation of order)
2. WIP Calculation KKAO/KKAX(Status of order should be REL or PDLV)
3. Variance Calculation KSS1/KSS2(Status of order should be DLV or TECO)
4. Order settlement CO88/KO88
5. Order closed.

If we go for any t-code for collective process, we have option for input is Plant, selection box of production order and period/Year.

Now concern is that using any t-code system select all order which is open for that period for example 003.2016. In my current project SAP implemented client in 2007 but still not calculated variance and not done the settlement so balance is at order level.

If I want to close all old order, first I need to clear the balance, for clearing the balance I need to do settlement for settlement need to do variance calculation.

but my problem is order is huge per plant more than 10,00,000/-. So system is taking too much time. For 4lac order for variance calculation system taken 83 hrs  almost 3.48 days only for calculation of variance.

We only want order after 01.05.2016 for period end closing, older order not required, also in future system should not select for period end closing.

  As one time activity, do I need to complete all above process, so that in future client will not face any issue.

Thanks

Akesh Agrawal