Hi Sugan,
You will need to setup some coverage for your finished products. The forecast that you load in MD61 is the best possible estimation made by the business of the sales. Knowing that this is an estimation, most of the companies work with coverage in order to ensure Service Level.
So this coverage will give you the addition inventory needed to react when you have those emergency sales orders.
The procurement lead time is the planned delivery time. You can enter the planned delivery time in your Purchasing info records and/or in the Material Master. The system will give priority to the Purchasing Info Record value.
Anyway, we can say that the total procurement time would be:
Planned Lead Time (Purc.Info Record / Material Master) + GR processing time + Purchase processing time (maintained in OMEW)
Thanks and Regards,
Mariano