So now that we covered some of the basic setups for MRP – let’s run MRP and see what happens.
(remember, we’re just scratching the surface here…one step at a time)
For your reference or catch up:
- How to setup your warehouses for MRP
- How to setup the Planning Tab for Parts
- What is the Inherit Demand Warehouse Option?
From VISUAL’s Material Planning Window, select Material Requirement Planning from the FILE menu
In the following window, you have several options to choose from that will affect how MRP will execute and plan your supply orders.
On the left, you have the options on WHERE you want to run MRP …
- across ALL your warehouses, OR
- plan each INDEPENDENTLY planned warehouse separately, OR
- just plan your UNIVERSAL warehouses
As for the options on the right, let’s start with the first 2 radio buttons …
Regeneration OR New Change?
Regeneration (1st radio button) processes ALL parts (from the top down) to determine any shortfalls between supply and demand and will generate planned orders for parts accordingly based the defined Order Policy under the part’s Planning Tab
Net Change (2nd radio button) looks at only those parts which have had activity since the last time you ran MRP. Note: Deleting a planned order of a part is not considered an “activity” on its own – so just know that this activity alone will not flag a part to be included in a Net Change MRP run.
Regeneration should be run at least once a week to ensure that all parts are processed
Single Pass
MRP is an interactive and dynamic process – it will evaluate ALL parts until planned orders cover ALL supply shortfalls.
When MRP generates planned supply orders – these planned supply orders themselves can create demand (for sub-components) that will in turn generate additional planned supply orders
If you select Single Pass – MRP will only do one pass, which could result in parts having newly created demand but may not have planned orders created for them if MRP created the demand after the first pass.
Clear as mud?
Let’s say that part ABC is used in part XYZ and there is demand on part XYZ…
MRP will evaluate ABC first and see no demand, it will then move on to XYZ and create a planned order.
Only in the second pass will MRP find that there is now demand for ABC and create a planned order for it.
MRP will keep running passes until there is no more shortfalls in supply
So, in a Single Pass scenario, only a planned order for XYZ will be created
Why use single pass? Well – you may want this if you are wanting to run MRP during production hours and don’t want to use up too much system resources evaluating – especially if you have complex, deep and multi-level BOMs – that would require many, many many passes.
MRP Exception Marking Limits
This allows you to configure MRP to evaluate based on a horizon or time frame – which you may consider as a “firm” schedule.
I suggest selecting NO HORIZON – basically have MRP evaluate all demand – regardless of how far out they may be in the future. You can then easily focus on the amount of orders to look at by filtering on a date range/time frame.
If you do want to set a horizon for MRP to evaluate- you are free to do so. The option Plus part leadtime ensures that MRP evaluates demand for a part within the part’s leadtime so that planned orders will be created in time – so the horizon then varies for each part.
Other Options
The next 2 options, Net on-hand quantities and Apply Min/Max/Multiple, are available to use if you use Advanced MRP and have parts that are Master Scheduled.
If you happen to use Advanced MRP…
- Net on-hand quantities for master scheduled parts – MRP will subtract nettable, on-hand balances from the total demand.
- Apply Min/Max/Multiple to master scheduled parts – MRP will use these values (if present) in evaluating and creating planned orders.
Exclude On-hold Customer Orders – MRP will exclude these customer orders when evaluating demand
Exclude Unreleased Work Orders – MRP will exclude these work orders when evaluating supply and demand.
Enable netting message – This will display a message if the processing of a part exceeds 10 seconds. Don’t enable this – it just slows down everything
Log MRP – This option will create a log file detailing MRP process and steps taken. Great source/tool for troubleshooting issues (if any) with MRP and unexpected results
