MRP calculation

MRP > MRP Wizard > Calculation > MRP calculation

Material requirements for a production process can be planned in the order recommendation. Material requirements are determined by the MRP calculation and are based on the current stock and forecasts. The requirement or planned requirement is compared to the stock and inflow and the recommendation is prepared.

An accurate calculation requires correct data and settings. Therefore, a data check is provided by MRP. The most important items in master data are checked. If any errors are found, a note is issued before starting the calculation.

Peggings made in the past are taken into account. If there are peggings in the past, a correct balance calculation is not possible. Correct the delivery dates, that are in the past or cannot be met anymore.

Negative amounts:

A correct requirement computation is not possible, if there is negative stock. We strongly recommend our users to deactivate negative stock in SAP Business One.

Requirements include:

•Customer Orders

•Calculations which are associated with the customer orders

•Projections

•Manufacturing Disposals (BOM)

•Forecasts

•Minimum stock

•If necessary, third-party systems

Inflow can be:

•Goods receipt from production orders

•Production requirements

•Requisitions

•If necessary, third-party systems

The current inventory is the sum of all the stocks:

•Without taking into account blocked items

•Excluding storage are for blocked stock

Receiving storage locations, storage for provisions and other stores are taken into account.

Note: Only valid, not blocked items, and non-phantom items are are taken into account. Additionally, the "stock item" and "planning system" parameters must be activated. The item must be a "Purchased part" item  or "Breakdown" must be defined as "Make".

In the results only items with a requirement are displayed. If all items are to be displayed, regardless of the requirement, set the filter to "show all" in the result window to display all selected items in the scenario.

Note: Regardless of the settings, all items are computed. For more information, see Planning scenarios – Detail – Item.

Multi-level - Calculation of delivery date

On the breakdown of the assembly BoM, the stored routing is taken into account and the demand is scheduled accordingly, as long as goods are not reserved. See Configuration wizard – Production – Reservation and Requirement coverage calculation.

The Delivery date is calculated using standard capacity planning with forward simulation. Existing dispatching is not considered and no resources are assigned.

The following factors affect the calculation:

•the routing stored in the item

•the resource stored in the routing

•the day capacity defined in the company calendar

For more information on the calculation function: see capacity planning.

Exception:

If a calculation is stored in a customer order, the dissolution is subject to the parameters of the associated calculation. If a production order has already been created, the requirements from the production order are used and the calculation and master data are ignored.

Warning: If the calculation contains assemblies, which are produced as order-oriented, these are not automatically established at the creation of the production order. In this case, a gap arises in the requirements calculation. Therefore, only order-related assemblies may be used for order-related calculations. The assembly MRP indicator in the calculation is used and not the one from master data.

NOTE on lead time calculation of sub-assemblies:

ATTENTION: In case of sub-assemblies, the parameter only affects lead time calculation of order-related sub-assemblies used as WO BoM! For storage-related sub-assemblies, the system uses fix lead time defined in Item master data.

Forecasts

With forecasts the requirement can be scheduled before the actual receipt of customer orders. Any projections can be defined and taken into consideration in the order proposal list.

Forecasts can be scheduled daily, weekly or monthly. Forecasts are defined  in SBO > MRP > Forecasts.

Forecasts are taken into account if:

•They are in the future

•Requirements are not covered by customer orders

Example: There is a forecast of 20 and customer orders of 10, the prognosis for the requirements calculation is reduced to 10.

Monthly forecast: In the current month only the remaining percentage of the requirements are taken into account. Requirements for this month: Daily requirements for the month * remaining days of the month.

Example: It is 10th January and for this month there is a forecast for 100 units. Requirement is calculated: (100/31 days) * 21 days remaining = demand of 67.7 for the remainder of January.

Multistage: Forecasts are always broken down. Existing stock is not included.

Note: The SBO > Administration > System Initialization > General Settings > Planning setting has no influence on the Beas – Order proposal calculation.

Priorities

Priorities are considered.

Minimum / Maximum stock

Minimum stock: From the desired inventory or minimum stock, the higher value is taken into account.

Example: Desired inventory = 10, minimum stock = 5, desired inventory of 10 is used.

Phantom assemblies

A phantom assembly itself is not displayed, but its BoM is (at multi-level calculation).