mrpopenbravo

8/8/2019 mrpopenbravo

http://slidepdf.com/reader/full/mrpopenbravo 1/9

terial Requirements Planning - An Introduction

2 MRP Concepts o 2.1 Material Requisitions

o 2.2 Sales Forecast o 2.3 Planning method

o 2.4 Planner 3 Configuring MRP in Openbravo

o 3.1 Product Configuration o 3.2 Vendor Configuration

o 3.3 Process Plan Configuration

4 Manufacturing Plan

o 4.1 Process Manufacturing Plan Logic 4.1.1 Initialization

4.1.2 Explode product tree 4.1.3 Process plan

o 4.2 Create Work Requirements Logic

o 4.3 Create Material Requirements Logic 5 Purchasing Plan

o 5.1 Process Purchasing Plan Logic

o 5.2 Create Purchase Order Logic 6 How to MRP

Material Requirements Planning - An Introduction

From Wikipedia Material Requirements Planning (MRP) is a software based production planning and

nventory control system used to manage manufacturing processes. Although it is not common nowadays, it s possible to conduct MRP by hand as well.

An MRP system is intended to simultaneously meet 3 objectives:

y Ensure that materials and products are available for production and delivery to customers.

y Maintain the lowest possible level of inventory. y Plan manufacturing activities, delivery schedules and purchasing activities.

The MRP module is structured in two main processes:

y Manufacturing plan: It recommends work requirements and material requirements. The inputs for this process are stocks, sales and purchase orders, open work requirements and sales forecasts. The

inputs are filtered by the planning method . The use of this process implies the use of OB's Manufacturing module.

y Purchase plan: It generates purchase orders using as inputs material requirements, stocks, salesand purchase orders and sales forecasts. The inputs are filtered by the planning method . This

process can be run after the Manufacturing Plan or be independent of production, in which case it isnot necessary to include the manufacturing.



During the planning processes, MRP assumes infinite capacity for different production plans or purchases. This means that the system will schedule a work requirement during the necessary days according to the

apacity defined in the product, but it can plan additional work requirements during the same day althoughhey use the same resources.

MRP Concepts

Material Requisitions

This section should be moved to the Procurement Management functional documentation

Material Requisitions are demands for products to be purchased. They are the output of the Production Plan

rocess - which creates demand for raw material - and a possible input of the Purchase Plan process.

Each requirement is identified by a document number and it is composed of one or more lines, one per

needed product and date combination. For each line, the following attributes are specified:

y Product

y Need by datey Requested quantity



y Vendor (optional)y Price list (optional)

y Price (optional)y Currency (optional)

Sales Forecast

S ales Forecasts are a projection of customer demand for a given product or expected sales for customers.

They can be used as inputs in the Manufacturing Plan and in the Purchasing Plan.

The key attributes of a sales forecast are:

y Business partner: the customer to whom you forecast the sale

y Date (optional): the date on which you enter the forecast - you can use this attribute to version theforecast.

A forecast is made of several lines; each line specifies the product for which you expect demand, the datewhen you expect the sale to occur, and the quantity expected be sold.

Planning method

The planning method is used to set the different transaction types that are considered during the planningprocess, as either supply or demand.

The planning method is a property of the product so different products can have a different planningmethod.

The available transaction classes for the planning method are:

y Requisitions (Material Forecast)

y Purchase Orders in progressy Sales Forecasts

y Sales Orders in progressy Work Requirement in progress

For each transaction type, it is also possible to define whether transactions are considered for the whole timehorizon or just for a portion:

y Days from start: the number of days from the beginning of the planning period to the start of thetransaction time frame being considered.

y Days to end: the number of days from the beginning of the planning horizon up to which

transactions are considered.

You can also specify the percentage of quantity to be considered using the Weighting attribute. For xample, if you specify a weight of 0.9 for Sales Forecast, if you provide a forecast of 100 units for a

pecific product, the planning method will only consider 90 units.



Planner

The Planner is an entity used to filter the products considered in the planning processes. On each purchase

or manufacturing plan is possible to select a planner so only products associated with that planner areonsidered.

Typically, in an enterprise, different people are responsible for planning manufacturing and purchasing of different products. You can use Planners to model that practice.

Please notice that in the manufacturing plan process other products can be included when the product tree is

xploded, see Manufacturing Plan section.

Configuring MRP in Openbravo

For the planning processes to work correctly, you have to properly configure the products and the vendors.

Before starting it is needed to create the necessary planning methods and planners as they are required in the

product configuration. It is very important to pay attention to the organizations where the products andvendors are being configured.

Product Configuration

The products have to be configured for each organization that performs manufacturing or purchase

planning. You can do this in the Product definition window, in the Org Specific tab. The relevant attributesre:

y Default Process Plan: required for manufactured products.

y Planning Method : the planning method to use. y Planner : the planner responsible for the product in the organization.

y C apacity: the maximum daily capacity for the product, to purchase or to produce. If the demandexceeds the capacity, the proposal will extend beyond one day.

y Min. Quantity: the minimum quantity that can be purchased or to produced. y Qty. Type: defines how the quantity of the proposals is calculated.

o Exact , each proposal is for this exact quantity and MRP recommends as many purchase or work requirements as necessary to fulfill the demand. For example, if this value is 10 and the

demand is for 55, 6 proposals for 10 each are recommended. o Multiple, the proposal quantity is a multiple of this quantity. For example, if this value is 10

and the demand is 55, one proposal for 60 is recommended. o If no type is defined the proposals are created with the needed quantity.

y Minimum lead time: minimum lead time in days to complete the proposal. For example, if this valueis 10 and a product is needed for October 30th, MRP suggests initiating purchasing or production on

October 20th. y S afety stock : minimum stock level to maintain during the planning processes. For example, if this

value is 50 and the quantity on hand is 100, for a demand of 60, MRP suggests to purchase or produce 10.



Vendor Configuration

Further, to process the purchase plan it is necessary to set at least one current vendor for the products. For

ach product and vendor, you can specify:

y Minimum purchase quantityy Promised delivery time (in days)y Minimum order quantity

y Quantity typey Capacity.

n the purchase plan process, if these data is not defined for the selected vendor, it is defaulted from the

values specified at product and organization level.

Process Plan Configuration

The correct definition of a process plan is essential for the correct execution of MRP as the process plans isneeded to explode the product demand.

MRP, however, does not have any additional configuration options for process plans beyond what isequired for Production Management.

Manufacturing Plan

Openbravo's manufacturing plan consists in creating work requirements and material requirements based onroduct demand. This process explodes all the product tree so all related products are planned. The source

of material demand can be sales orders and sales forecasts. During the planning process it also takes intoccount current stock, minimum stocks, unreceived purchase orders and open work requirements.

When processing the plan, the products to be planned can be selected using several filters:

y Producty Product category: all products in the category

y Planner: all the products associated with the planner y Customer: all the products purchased by the customers

y Partner group: all the products purchased by the customers of the group.

Please notice that this filter is only used at the beginning of the process but product selection grows as theproduct tree is exploded.

For example, in the following image, all the products will be planned when at least one of them fulfills theilter . When product C is planned it is necessary to plan the demand of its intermediate product F . The

demand for F is driven by C but also by product B, which is then also planned. Similarly, to plan F it isnecessary to also plan the raw materials product I and product J .

Continuing with this explosion process, we see that all the products in the tree need to be planned.



When the product tree is exploded, the planning process generates proposal lines that are linked to each

other with a parent-child relationship. Every product demand has its own work requirement proposal or material requirement proposal. Each work

equirement proposal has different child lines, the main one is to manufacture the correspondent materialequirement, and the children are for the products that are used and that might be created in the work

equirement.

After the Manufacturing Planning process, it is possible to manually adjust the work requirement or material

equirement recommended by MRP by editing quantities and dates. When editing a work requirement, you only need to change the main line; you can then recalculate the dates

nd quantities of all the children lines by pressing the Recalculate button.

To put the manufacturing plan into execution, it is necessary to create the work requirement and material

equirements from all the proposals using the correspondent processes. The created Work Requirements only have the header so it is necessary to process it to create the operations

nd products. This is to allow a final review before initiating production.

Process Manufacturing Plan Logic

The manufacturing plan process is structured in three different steps. Before starting these steps the

manufacturing plan lines that are not fixed are deleted, normally these lines are the proposals created inprevious execution of the process. And all the remaining lines are set as not exploded except the lines of

products that are manufactured in a work requirement in progress as the lines of the products that areonsumed in that work requirements will already exist.



This section is still to be completed.

Purchasing Plan

Openbravo's purchasing plan process creates purchase orders based on the product demand for purchased

products. This process doesn't explode the manufacturing products so it is necessary to get or set the rawmaterials demand prior to completing the purchasing plan.

The source of material demand can be sales orders, material requirements and sales forecasts. During the

planning process, current stock , minimum stocks and unreceived purchase orders are also taken intoccount.

Then you can begin the process by creating a purchasing plan record for a date and a time horizon.

You can specify the products to be planned based on several filters:

y Producty Product category: all products of the category are planned

y Planner: all the products associated with the planner y Customer: all the products purchased by the customers

y Partner group: all the products purchased by the customers of the group. y Vendor: all the products which current vendor is the selected vendor .

You can then initiate the process by pressing the Process Purchasing Plan button. This action considers thedemand for each product as defined in its Planning Method and generates purchase order proposals. The

vendor for the proposal is defaulted from the vendor specified on the Purchasing Plan and the need by dateprecedes the required date by the number of days specified in the Lead Time attribute of the Purchasing

Plan.

Once the purchase order proposals are created, you can review them and manually modify them if needed.

Finally You can then launch the C reate Purchase Orders process pressing the corresponding button. Theprocess creates purchase orders in draft status so it is necessary to process them later .



Process Purchasing Plan Logic

The first step is to initialize the products to be planned. The initialization consists on including in theprocess all the transactions expected to happen during the defined time period and that fulfills the planning

method of each product. To know if a product has been initialized or not, the existence of inserted stock

ines is checked.

The stock lines are always included.

For the purchase plan process are considered thepurchase and sales orders, the sales forecasts and the pending requisitions.

Once the products are initialized, the proper planning process begins. The results of this planning are thepurchase proposals. This process is done product by product. For each product, all the lines are considered

ordered by date. If there is more than one expected transaction on the same date the priority order is: 1stCurrent stock, 2nd Minimum stock of the product, 3rd Positive quantity transactions and 4th Negative

quantity transactions.

During the processing of each product,the expected stock for each transaction is stored. When the stock

eaches negative levels a purchase proposal is created. To create the proposal are taken into account the

estrictions of the current vendor, capacity and stock types and quantities.

For each proposal, two differentdates are calculated, one the day when the product is needed and, the second, the day when it should beordered in order to arrive on time. When a proposal for a needed date already exists, the process changes the

quantity of the existing one instead of creating a new one. The vendor of the proposal must be a currentvendor of the process, if a vendor is set for the purchase plan process then that vendor is used.

Create Purchase Order Logic

The C reate Purchase Orders process generates orders from all the purchase proposals of the planning

process. If a proposal already has an associated order line, it is considered already processed and it isdiscarded in this process. These generated purchase orders are created in draft mode.

One purchase order for each vendor of the proposals is created. The document and order date in the header of the purchase order is the same as the date of the purchasing plan. Each order line corresponds with a

purchase proposal. The promised and order dates of the order line are the needed and order date of theproposal.

The pricing of the order is generated using the purchase price list of the vendor . If the current version of the

price list doesn't include the product the process throws an error . The price is calculated taking into accounthe possible price modifiers (offers); the corresponding taxes are also included.

f the purchase plan has a description, it is copied in the headers of the purchase orders.

mrpopenbravo

Documents