Just in time manufacturing only responds to current demand

Just in time manufacturing only responds to current demand within item planning period action windows.  This is highly useful for handling blanket sales orders from customers because it isolates current demand that may need action now from long term demand that can be actioned upon later.


What is the item planning period action window?


Each top level manufactured item has its own item planning period action window, which consists of the item’s Lead Days plus Job Days allocations, as well as the system MRP Interval setting and any non-workdays that get encountered.  Essentially, the planning period provides sufficient time to manufacture the item should it have to be made to order. 


Long term demand is ignored by MRP 

Only sales order line items with required dates that fall within the item’s planning period are included by MRP in net demand calculations.  Any long term demand outside the planning period is ignored by MRP because there is ample time to manufacture the item later if needed when that demand eventually falls into the planning period and becomes current.

The item planning period keeps inventory and WIP lean and efficient 


The item planning period is the means by which jobs are generated “just in time” instead of prematurely before they are actually needed, which keeps inventory and work in process lean and efficient. 


Blanket sales orders can be freely entered

You can freely enter blanket sales orders with future required dates and quantities because MRP will automatically respond to each required date when it eventually falls into the item’s planning period action window.


Blanket sales orders can be entered two ways

 Blanket sales orders can be entered two ways.  The ideal method that gives the most control over picking, shipping, invoicing, and order closing is to enter a set of sales orders, each for its own required date and quantity, all tied together with common reference to the customer’s purchase order number.  The other less ideal method is to enter multiple required dates and quantities on a single sales order that stays continuously open for multiple pick batches, shipments, and invoices.