01
Input data
Plan, product structure, inventory and delivery.
MRP
MRP — material requirements planning
MRP answers what is needed, how much and by when to fulfil the plan. It connects the product structure with inventory, delivery dates and demand.
02
Material balance
From gross demand to actual shortage.
03
Planner's decision
Quantity and date with visible assumptions.
01Guide/MRP
The input determines the outcome
The calculations use the product's material structure (BOM), quantities to be made, available inventory, reservations, open deliveries and lead times. A missing BOM version or an outdated supplier deadline can distort the plan.
We also determine batch sizes, safety stock rules and replacement materials. The system should not hide the assumptions on which it bases the purchase proposal.
02Guide/MRP
Example: component shortage
Let's assume an order for 100 products, each of which uses two components. If 60 pieces are available, there are no other needs or confirmed supplies, the shortage is 140 pieces. MRP ties this quantity to the deadline, taking into account the time it takes to obtain the material.
When the order, consumption or delivery date changes, the balance must be recalculated. The user should be able to see the source of the change and the items requiring decisions.
- 100 products
Order to be fulfilled.
- × 2 components
200 pieces of gross requirement.
- − 60 available
Stock without other reservations.
- 140 missing
Need to associate with a term.
The example ignores supplies, other needs, safety stock, and batch rounding. The actual plan takes into account the agreed rules.
03Guide/MRP
Materials are not production capacity
The available material does not prove that the machine and operator will be free. Classic MRP focuses on balancing material needs; Resource constraints require additional planning.
MRP often runs in ERP. It uses warehouse, purchasing and production information, and its results must be agreed with the people planning the implementation.
04Changes and decisions
The planning result changes with the assumptions
A postponed delivery, a new version of the product structure, or a larger order can change the needs of many items. The planner should see the cause and effect of the change, not just the new quantity to order.
We determine when a proposal requires approval and how to treat orders already sent to the supplier. Frequent recalculation of the plan should not overwrite obligations without control.
Delivery date
Verify that the material will arrive before starting the operation that consumes it.
Purchase batch
Minimum quantity or multiple packing can raise the quantity ordered beyond the sheer shortage.
BOM change
Indicate the version of the structure applicable to a given order and compatible units of measurement.
Replacement material
Admission of a substitute and its quantity requires a technological rule and a decision of an authorized person.
Comparison
What goes into MRP and what results from it?
| Input data | Meaning | Result or decision |
|---|---|---|
| Plan and orders | How many products and for what date. | Material needs over time. |
| Product structure / BOM | Ingredients and consumption per unit. | Expanding the needs for components. |
| Inventory and open supplies | What is available or confirmed. | Net needs and deadlines at risk. |
| Times and parties | How long does it take to obtain and in what quantities. | Proposed quantity and order date. |
Questions and answers
Before making a decision
Will MRP guarantee no inventory or downtime?
NO. It helps you plan based on data and rules. Delayed deliveries, BOM errors and changes in demand still require decisions and plan updates.
Will MRP predict future demand?
Classic MRP calculates the plan and material needs. Demand forecast can be one of the inputs, but it requires its own assumptions and verification.
How to start preparing data?
From a reliable product structure, units, states, open deliveries and deadlines. First, we go through several sample products by hand.
Let’s start with a conversation
How will MRP help your team?
Describe the data-missing decision and your current workflow. We will determine the scope of the solution and the role of existing tools.
Discuss MRP needs