How-to MRP

This document is still a work in progress. It may contain inaccuracies or errors.

How-to MRP - An Introduction

In this document it is explained a complete example of the MRP from its configuration to the creation of needed purchase orders for raw materials. It is used the 2.35 MP4 version of Openbravo ERP.

This document is a complement to the existing functional documentation of the MRP so in this document is not going to be explained what is each used element.

The used example is a fictional enterprise that manufactures usb cables. In the how to are created the raw materials (copper, plastic and plugs), intermediate products (cable) and final product (usb-cable). There is also created the process plan and all the necessary setup for the MRP.

MRP Setup

The steps on this section doesn't follow a fixed order although some of them must be created before others. You can follow the desired order, but it is important to go through all the steps for a correct execution of the MRP.

Planner

It is created the Planner Planner 1. The planner will be mandatory in the product configuration for the MRP.

Planning Method

It is created a unique Planning method Complete 30 days that includes all the transactions with weighting 1 and Days to End 30.

Products

All the products are created under the new product category Cables and are checked as production products.

In the following table is shown all the relevant configuration of the products, the process plan has to be updated on the product later when it is created. The MRP specifics are defined in the Org specific tab, for raw materials are also inserted in the Purchasing tab (it is used Anghet ,Company as current vendor). The intermediate product Cable is not considered in the MRP as all the cable created in the process plan is consumed in the same process plan to produce the usb cable. The raw materials and the finished products are also included in a price list: 01-01-2005 Special nº1 for the Usb cable and 01/01/2005 Purchase for Copper, Plastic and Plugs

Process Plan

Prior to create the Process Plan it is necessary to properly setup the manufacturing module, in this example are created just 2 Activities, Build cable and Ensemble USB Cable.

It is created the Process Plan 'Usb Cables', with one version valid from 2008-01-01 to 2008-12-31. The Process plan has 2 operations defined using the following table.

MRP Execution

Once the MRP has been set up it is possible to start running the MRP processes. In this example is created a Sales Order of USB cables and a Work Requirement for USB Cables that it is not enough to fulfill the Sales Order.

Insert demand

Create and complete a Sales Order using a document type that does not generate the corresponding shipment, in this case is used the Standard Order and a Scheduled delivery date 2008-07-07. The order has a unique line for 500 USB Cables.

Create and process a Work Requirement for 100 Usb Cable. The three dates are the same 2008-08-05.

Manufacturing Plan

Create a new Manufacturing Plan.

• Name: Manufacturing Plan 1
• Document Date: 2008-06-15
• Time Horizon: 60
• Lead Time: 1
• Planner: Planner 1

After processing the plan 10 lines are inserted in the Lines tab. We can see how it has considered the Sales Order, but not the Work Requirement because its Launch WR Date (2008-08-05) is later than the 30 days limit set in the Planning Method.

On the Document Date we can see the 2 lines related to the stock of the products that are being planned, in this case only the Usb Cable, as the Raw Materials are purchased.If the USB Cable had an intermediate product that was produced in a different Process plan it would have appeared here with its own Work Requirement suggestion if necessary.

The remaining lines are related to the sales order. As the order is promised for July 7th and the Lead Time is 1 the MRP suggest a Work Requirement that would finish on July 6th. This Work Requirement is of 600 units because it is considering also the Minimum stock of 100 units. This Work Requirement consumes some raw materials at June 30th that is when is expected to start the production. This leads to material requirements suggestions for the day before. In the requirements in the Planned Order date is also calculated when should be ordered this products to arrive on time.

Create Requisitions and Work Requirements

Once the results are checked it is possible to Create the Material Requirements (or Requisitions) and the Work Requirement with the correspondent buttons of the header.

Purchasing Plan

Create Purchase Orders