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Calculating the Planning Worksheet (Running MPS/MRP)

The terms "running the planning worksheet" or "running MRP" refer to the calculation of the master production schedule and material requirements based on actual and forecasted demand. The planning system can calculate either Master Planning Schedule (MPS) or Material Requirements Planning (MRP) on request, or it can calculate both at the same time.

The planning algorithms used for both MPS and MRP are identical. The planning algorithms concern netting, reuse of existing replenishment orders, and action messages. The planning system process looks at what is needed or will be needed (demand) and what is on-hand or expected (supply.) When these quantities are netted against each other, the program provides Action Messages. Action messages are suggestions to create a new order, change an order (quantity or date), or cancel an order in order. The term "order" includes production orders, purchase orders, and transfer orders.

Proper planning results depend on the set up done on Item Cards, Production BOMs, and Routings.

Methods for Generating a Plan

Most companies have a specific process for generating a production plan, including the periodic requirements for plan generation; that is, how often, what method, and so on. These processes should be considered during the setup and implementation stage. Plans may be calculated in three ways:

With each planned method, the program generates worksheet entries assuming infinite capacity; work center and machine center capacity is not considered when developing schedules.

Attention

The Regenerative Plan is the most common process used for running MRP. The calculate planning worksheet and carry out action messages processes, however, can be used to run the Calculate Net Change Plan.

The Get Action Messages Plan can be run between net change and regenerative planning runs to get an immediate view of the impact of schedule changes, but it is not intended as a replacement of net change or regenerative planning.

To Calculate the Planning Worksheet:

The calculation of a materials plan is performed as follows:

  1. Open the Planning Worksheet window. This window is used for Regenerative/Net change planning and MPS/MRP.

  2. Click Functions, Calculate Regenerative Plan.

  3. On the Item tab you can filter and run the planning routines based on item, item description or location.

  4. The Options tab allows you to specify the type and horizon of the planning run:

ShowMPS

Placing a check mark in this field initiates the calculation of a master production schedule. Items with open sales orders and/or production forecasts are considered in this run.

ShowMRP

Placing a check mark in this field initiates the calculation of material requirements planning. Items with dependent requirements are considered in this run.

Typically, MPS and MRP are run simultaneously. To run MPS and MRP simultaneously, the Combined MPS/MRP Calculation check box must be checked on the Planning tab of the Manufacturing Setup window.

ShowOrder Date

This date is used to evaluate inventory availability. If an item's on-hand quantity is below the reorder point, the system forward-schedules a replenishment order from this date. If an item is below its safety stock (as of the order date), the system back-schedules a replenishment order due on the order date.

ShowEnding Date

This is the ending date of the planning horizon. Neither demand nor supply is considered after this date. If the reorder cycle for an item extends beyond the ending date, the effective planning horizon for that item is equal to the Order Date + Reorder Cycle.

The planning horizon is the amount of time the plan is extended to. If the horizon is too short, items with a longer lead time are not ordered on time. If the horizon is too long, too much time is spent reviewing and processing information that likely changes before it is needed. It is possible to set one planning horizon for production and a longer one for purchases, although it is not required. A planning horizon for purchases and production should be set to cover the cumulative lead time for components.

ShowStop and Show First Error

If you place a check mark in this field, the planning run will stop as soon as it encounters an error. At the same time, a message is displayed with information about the (first) error. If an error exists, only the successful planning lines made before the error was encountered will be presented in the planning worksheet.

If you leave the field unchecked, the Calculate Plan batch job will continue until it has completed, that is, errors will not interrupt the batch job. If one or more errors exist, the program will display a message after completion saying how many items are affected. The Planning Error Log window will then open to provide more details about the error and links to the affected item card(s).

ShowUse Forecast

In this field you select a forecast that should be included as demand when running the planning batch job. The default forecast is set up on the Planning tab of the Manufacturing Setup window.

ShowExclude Forecast Before

In this field you define how much of the selected forecast to include in the planning run by entering a date before which forecast demand is not included, thus allowing you to exclude old information.

  1. Click OK. The batch job runs and then the planning worksheet is populated with the planning lines. For help on a specific field, click in the field and press F1.

Action Messages

Action messages are issued by the order tracking system when balance is unattainable within the existing order network. They can be viewed as a suggestion for you to process changes that reestablish equilibrium between supply and demand.

The generation of action messages occurs one level at a time, with respect to each item's low-level code. This ensures that all items that experience or will experience changes in supply or demand are considered.

To avoid small, superfluous or unimportant action messages, the user can establish dampeners, which serve to restrict the generation of action messages to only those changes that exceed the defined quantity or number of days.

In response to any supply/demand imbalances, the program generates the following action messages:

ShowNew

If a demand cannot be fulfilled by suggesting action messages to Change Qty., Reschedule, or Reschedule & Change on existing orders, the system generates Action Message = New, which suggests a new order. In addition, the system issues action message New if there are no existing supply orders within the reorder cycle of the item in question. This parameter determines the number of periods forward and backward in the availability profile when searching for an order to reschedule.

ShowChange Quantity

When demand that is tracked to a supply order(s) experiences a quantity change, the system generates Action Message = Change Qty., which indicates that the related supply should be changed relative to the change in demand. If a new demand emerges, the system searches for the nearest existing unreserved supply order within the reorder cycle, and issues a Change Action Message for that order.

ShowReschedule

When a supply or demand order experiences a date modification causing an imbalance in the order network, the system issues Action Message = Reschedule. If there is a one-to-one relationship between demand and supply, the system issues an action message suggesting that the supply order be moved accordingly. If the supply-order covers demand from more than one sales order, the supply order is re-scheduled equal to the date of the first demand.

ShowReschedule and Change Quantity

If both the dates and quantities of an order have been modified, it is necessary to change plans with regard to both circumstances. Action messaging gathers both actions in one message, Resched. and Chg. Qty., to ensure that the order network returns to balance.

ShowCancel

If a demand, which has been covered on an order-to-order basis, is deleted, the system issues an Action Message to Cancel the related supply order(s). If the relationship is not order-to-order, the system generates an action message to Change in order to reduce the supply. If through other factors, such as inventory adjustments, a supply order is not required at the time the action messages are generated by the user, the system suggests Action Message = Cancel in the worksheet.

Note

An Action Message is a suggestion to create a new order, cancel an order, or change the quantity or date of an order. An order is a purchase order, transfer order, or production order.

To Carry Out Action Messages:

Once you have reviewed the action messages and determined whether to accept some or all of the suggested changes – by checking or unchecking the Accept Action Message field – you are ready to update the schedules accordingly.

  1. On the calculated Planning Worksheet, click Functions, Carry Out Action Message. The Carry Out Action Msg. - Plan. batch job has two tabs: Planning Line and Options.

  2. On the Planning Line tab you can set filters to limit the carry out action messages.

  3. On the Options tab, you choose which types of orders you want to create and whether lines need to be moved to the Requisition Worksheet:

ShowProduction Order

In this field, you can specify whether you want to create production orders in the Manufacturing application area. You can do this directly from the planning line proposals. You can create either planned or firm planned production orders.

ShowPurchase Order

In this field, you can specify whether you want to create purchase orders in the Purchases & Payables application area. You can do this directly from the planning line proposals.

ShowTemplate Name

If you have chosen to copy the planning line proposals for purchase orders to the requisition worksheet, this field becomes editable. You can select the template name here.

ShowWorksheet Name

If you have chosen to copy the planning line proposals for purchase orders to the requisition worksheet, this field becomes editable. You can select the worksheet name here.

ShowTransfer Order

In this field, you can specify whether you want to create transfer orders in the Inventory application area. You can do this directly from the planning line proposals.

ShowTemplate Name

If you have chosen to copy the planning line proposals for transfer orders to the requisition worksheet, this field becomes editable. You can select the template name here.

ShowWorksheet Name

If you have chosen to copy the planning line proposals for transfer orders to the requisition worksheet, this field becomes editable. You can select the worksheet name here.

ShowStop and Show First Error

If you place a check mark in this field, the Carry Out Action Msg. - Plan. batch job will stop as soon as it encounters an error. At the same time, a message is displayed with information about the (first) error. If an error exists, only the planning lines processed before the error was encountered will result in supply orders.

If you leave the field unchecked, the Carry Out Action Msg. - Plan. batch job will continue until it has completed, that is, errors will not interrupt the batch job. If one or more errors exist, the program will display a message after completion saying how many items are affected.

  1. Click OK.

The batch job deletes the lines in the planning worksheet after it has performed the action message. The other lines remain in the planning worksheet until they are either accepted at a later date or else deleted. You can also delete the lines manually.

Related Topics

Create a Production BOM

Create a Routing

Create an Item Card

Plan for New Demand

Refreshing Planning Demands

Tracking Entries in Planning Lines

Viewing Item Availability in the Planning Worksheet

Quick guides for manufacturing are available in a document that you can edit and print in Microsoft Office Word. The file, called Quick Guides – Manufacturing Foundation - Classic.doc, is installed in the documentation folder of your client installation.



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