Reverse planning in Microsoft Dynamics 365 Business Central lets you calculate the consequences of moving demands across your full production hierarchy. It works like a regular MRP run, but in the opposite direction. Instead of planning supply from demand, it starts at the lowest level and works its way up.
When you move a demand, reverse planning calculates low level code from the bottom up. It starts with the purchase items at the lowest level, moves through each subsequent low level code, and ends at low level code zero. This gives you all the demands and all the supplies across the complete hierarchy.
You can inspect which underlying supply changes cause each movement by viewing the supply changes per line. The reverse planning setup includes a check mark to hide the supply lines. Deselect it if you want to see both the movement lines and the lines that cause them directly in the journal.
How reverse planning calculates movements bottom up
When you calculate for moving demands with reverse planning, you select something like moving demands on a specific location. The system then calculates low level code from the bottom up. It has to start from the lowest item, which is the purchase item, then the next low level code, and so on, ending up with low level code zero.
The result contains all the demands and all the supplies in the full hierarchy. It works like a normal MRP, except it runs in the opposite direction.
Viewing the supply changes that cause a movement
Because reverse planning works through the full hierarchy, the journal contains lines that cause the movements. If you click on a single line, for example a City Bike, and view the supply changes, you can see what is driving it.
In one example, a front wheel causes the movement. When you scroll further, you can see there is a firm planned order with a due date and a new due date. The order is suggested to be moved, and as a consequence you need to move the City Bike order as well. This covers both the underlying supplies and inventory when you do not have enough on hand.
Filtering supply changes per line
You can see the supply changes per line, because there is a filter on the line. It is the same line as the normal reverse planning line. If you select a line and review the supply changes, the picture depends on how the item is supplied.
A line that uses replenishment from another site does not have any changes. If you take a different line, you can see its supply changes. By removing the filter, you can see all the supply changes causing all of the movements.
There is also a filter on hidden lines. If you remove that field as well, you can see the original line in the journal. That way you have access to all the lines, both the line that causes the movement and the resulting line.
Showing all lines directly in the journal
If you want to see the journal with all of the lines at once, that is possible too. To show both the movement and the causes directly, go into the reverse planning setup. There is a check mark that suggests to hide the supply lines.
If you deselect this check mark, the next time you run reverse planning you will see all of the lines directly in the journal, instead of having to open the supply changes per line.
Q&A
How does reverse planning differ from a normal MRP run?
Reverse planning works like a normal MRP, but in the opposite direction. It calculates low level code from the bottom up, starting with the lowest purchase item and ending at low level code zero, and it includes all demands and supplies across the full hierarchy.
How can I see what causes a suggested movement?
Click on the line in question and view the supply changes. You can trace the movement back to underlying supplies, such as a component with a firm planned order that has a new due date, as well as inventory shortages.
Why do some lines show no supply changes?
A line that is replenished from another site does not have any supply changes. Only lines with underlying supply or inventory consequences will show changes.
How do I show both the movement and its causes directly in the journal?
Open the reverse planning setup and deselect the check mark that hides the supply lines. The next time you run reverse planning, all the lines, including the causing lines, appear directly in the journal.