Standard MRP planning in Microsoft Dynamics 365 Business Central calculates backwards from your demand to figure out when supplies need to arrive. That works fine until a vendor tells you a delivery date is impossible. When that happens, MRP keeps suggesting the date you already know you can’t meet. Reverse planning solves this by moving the demand forward instead and calculating all the consequences up through the hierarchy, including the effect on your sales order lines.
Use reverse planning when a delivery is delayed and you need to push out a demand date rather than pull a supply in. Standard MRP cannot move demands forward to match a vendor’s actual delivery date. Reverse planning can.
Reverse planning takes one delayed item, moves its demand date, and finds every downstream effect. You see the new dates on related components such as your back wheel and front wheel, the postponed supply on the delayed item, and the resulting changes on your sales order lines.
The limitation in standard MRP planning
One of the classic issues with MRP planning is that it only calculates backwards. It starts from the supplies that matter, works backwards step by step, and ends up telling you when each item needs to be replenished to meet your demand.
That logic is fine when everything goes to plan. Imagine you run the standard planning worksheet on your production location code. Everything is optimised, all demands and supplies are in place, and the worksheet shows no lines. Nothing needs action.
What happens when a vendor cannot deliver on time
Now the situation changes. Your vendor in the Far East, the one who supplies your rubber parts, calls you about a tire you ordered. You had an agreement for delivery on 8 May, but he tells you the item can only be delivered on 20 May. The reason does not matter. It could be a delayed ship or any other cause. The fact is the original date is no longer possible.
When you look at the graphical profile for that item, you now see a negative situation. You have demand on a date that can no longer be met because the purchase order has been postponed.
Here is where standard MRP falls short. If you run the planning worksheet again with the exact same criteria as before, MRP calculates backwards and tells you that you need to replenish the item on an earlier date, because that is what the demand requires. But that is exactly what you cannot do. Your vendor already told you it is impossible. No matter how many times you recalculate, MRP keeps producing lines for that item on a date you cannot achieve.
How reverse planning moves the demand date forward
Instead of forcing the supply to an impossible date, you need a tool that moves the demand to match reality. That is what reverse planning does with its move demands function.
When you suggest moving demands using the template, the tool finds the affected item, moves it to the new feasible date, and works out all the consequences. It postpones the supply on the tire to the new delivery date and then pushes the related demands up through the bill of materials hierarchy.
In the result you can see the full picture. The supply chain for the affected item appears at the top, showing the postponement to the new date in August. Below that, you see the impact on the related components, such as your back wheel and front wheel, each with its new date. Further down, you see the consequences on your sales order lines.
The point is that you need something that can postpone all the demands up through the hierarchy when a supply slips. Standard MRP cannot do that on its own. Reverse planning with move demand dates handles it.
Q&A
Why can’t standard MRP handle a delayed vendor delivery?
Standard MRP only calculates backwards from demand to supply. When a vendor cannot meet the required date, MRP keeps suggesting that impossible date because it works back from what the demand needs, not from what the vendor can actually deliver.
What does reverse planning do differently?
Reverse planning moves the demand date forward to match the achievable delivery date and then calculates all the downstream consequences, including related components and sales order lines.
When should I use reverse planning instead of standard MRP?
Use reverse planning when a supply is delayed and you need to push demand dates out rather than pull supplies in. This is the situation standard MRP cannot resolve.
What does the reverse planning result show me?
It shows the postponed supply on the delayed item, the new dates on related components in the hierarchy, and the resulting impact on your sales order lines.