Reverse planning in Business Central lets you plan in different levels of urgency instead of running one full MRP calculation that mixes everything together. You start each day by finding the most critical items, the ones where your ending inventory goes below zero, and handle those first. You then work down through less urgent levels: items below safety stock, and items below reorder point.
You do this with templates in the Simple MRP Journal. The app ships with several out-of-the-box best practice templates, so you do not have to build the logic yourself. Each template uses a different trigger: below zero, below safety stock, or below reorder point.
Templates can be set to skip items that are already planned, so you avoid handling the same line twice as you move through the urgency levels. Once you have reviewed the suggestions and set action messages, you carry out actions to move the lines into the reverse planning worksheet, where you create purchase orders or production orders.
Planning in levels of urgency instead of one full MRP run
When you run a full MRP planning, everything gets planned in one go. That makes it difficult to handle the most important things first. You end up looking at a line that needs attention tomorrow or Friday right next to a line that concerns demand five weeks from now. There is no separation between what is urgent and what can wait.
Reverse planning solves this by letting you plan in different levels of urgency. You calculate using templates in the Simple MRP Journal, and each template focuses on a specific level of criticality. This way you handle the most critical items first and work your way down.
The most critical level: items below zero on ending inventory
The first template you use is the critical one: items below zero on the ending inventory. This is the most critical stuff. You look within a specific planning period, which could be one week or three months, and check whether you go below zero, and specifically whether you go below zero on the ending inventory of that period.
The distinction matters. You are not interested in dipping below zero somewhere in the middle of the planning period if a later supply brings you back up. In that case it is fine, and you just need to move the demand later on. What you care about is the ending inventory of the period.
In the example, this template finds two items where the ending inventory is below zero: a city bike and a New York Lady bike. So on Monday morning, the first thing you do is run this planning, find the items that are actually critical, and let the system suggest a quantity to order. You set the action message, carry out actions, and those two lines move into the reverse planning worksheet. From there you can handle them, or if you are not starting those production orders right now, you continue to the next level of urgency.
The second level: items below safety stock
The second template runs the same calculation, except it looks for items that go below safety stock within the period. Instead of planning on zero, you plan on safety stock, still measured on the ending inventory of the period. This shows you whether you need extra now and how many items fall into this level of planning.
This is the second most critical level. It runs on the same main location and the same dates, but you get more lines because you are now triggering on safety stock rather than zero. When you scroll right, you find items on the ending inventory that fall below safety stock.
As before, you can let the system suggest a quantity to order, or you can fill in the lines manually. You select actions one at a time or set all of them, whichever you prefer, then carry out actions to apply those lines to the reverse planning worksheet.
The third level: items below reorder point
The third template is the most common one. With safety stock at zero, you plan on reorder point. This template ignores the lines that are already planned, because they are already in the journal.
This works through a setting on the template card. When you check the template, there is a check mark labelled “skip if already planned.” If a line is already in the reverse planning worksheet, the template does not handle it again. That keeps each urgency level clean and avoids duplicate work.
Using the below reorder point template follows the same logic as the others, except now you are looking at the reorder point. In the example this leaves eight lines, the ones that trigger on reorder point but not on safety stock.
How the workflow fits your planning frequency
This approach lets you build up many different templates, each unfolding a lower level of critical stuff. You work through them from most urgent to least urgent. Then in the afternoon or evening of the first day, you create purchase orders and production orders, or carry out the actions depending on your planning frequency.
The result is a high level of flexibility for the planner. You decide how deep to go and when, rather than being forced to deal with everything in one pass.
Q&A
What is the advantage of reverse planning over a full MRP run?
Reverse planning lets you plan in different levels of urgency instead of planning everything in one go. With a full MRP run it is hard to handle the most important items first, because urgent lines sit next to lines that concern demand weeks ahead. Reverse planning separates the critical items from the less urgent ones.
Which template should you run first in the morning?
Start with the template that finds items below zero on the ending inventory. This is the most critical level. It identifies the items where you actually run short, so you can handle those before moving on to less urgent levels.
What is the difference between going below zero during the period and below zero on the ending inventory?
Going below zero during the planning period is acceptable if a later supply brings you back up, because you can just move the demand later. The ending inventory of the period is what matters. The critical template triggers only when the ending inventory goes below zero.
How do you avoid handling the same item in multiple urgency levels?
Use the “skip if already planned” check mark on the template card. When it is enabled, the template ignores any line that is already in the reverse planning worksheet, so you do not handle the same item twice as you work through the urgency levels.
What are the three typical urgency levels?
The three levels are: items below zero on ending inventory (most critical), items below safety stock (second most critical), and items below reorder point (the most common). Each uses a separate template with its own trigger.
Do you have to set up the templates yourself?
No. When you download the app, it comes with many out-of-the-box best practice templates you can use directly, including templates for critical items below zero, below safety stock, and below reorder point.