Enhancement in MD50 for "Determination of Basic Dates for Planned Orders" Scheduling type

Hi Experts,

We follows MTO production system in our company and our Deliverable materials (FERT) for which, we creates sale order has multilevel BOM.

We would want to determine the Basic start and finish date for all the In-house production materials while creating the planned order through MD50 by using Scheduling Type-1 (Determination of Basic Dates for Planned Orders).

Our problem is, In-house production time varies sale order to sale order for all the In-house production materials, because of which, we could not use the Material Master -MRP2 - In house production time field (MARC-DZEIT).

Our requirement is to maintain the In-house production time sale order wise for all the In-house production materials, so that we could do the scheduling effectively while creating the Planned orders in MD50.

Request experts opinion, whether this can be met through Standard or Customization is the only solution?

If Customization is the only solution, Can we have a Z-Table to maintain the In-house Production time Sale Order wise for all the materials, If so, Can enhancement be done in MD50 to refer the Z-Table's In-house production time field value in place of Material Master's In-house production time field (MARC-DZEIT) value?

It would be appreciated, if you could provide me the way forward for this requirement.

Thanks,

Vasanth.