Considerations

Batch/Online Options

The planner may wish to use a combination of the two facilities.  Two examples of how they might be used are presented below.

Option 1

1st evening:  Generate the tentative master schedule for all parts in batch mode.

Run the Key Facility Load Report against the tentative schedule.

2nd day:  Review and modify the schedules for more critical parts, or for parts creating capacity problems, using the online maintenance conversation.

Retest key facility problems using the online Key Facility Load Inquiry conversation.

2nd evening:  Generate the actual Master Schedule.

Run Requirements Planning.

Option 2

1st day:  Generate the tentative master schedule for more critical parts using the online facility.  Set the Bypass flag on for these parts, so that their schedules will not be changed during batch processing.

1st evening:  Generate the tentative master schedule for all parts in batch, bypassing those parts maintained online.

Run the Key Facility Load Report against the tentative schedule.

2nd Day:  Review and modify the schedules for parts creating capacity problems, using the online maintenance conversation.

Retest key facility problems using the online Key Facility Load Inquiry conversation.

2nd evening:  Generate the actual Master Schedule.

Run Requirements Planning.

Total Demand

The Master Scheduling and Requirements Planning modules calculate total demand using projected sales, unexpected sales, and dependent demand.  Throughout the Master Scheduling and Requirement Planning modules, the terms Projected Demand, Consumable Demand, Net Demand, Unplanned Demand, Unconsumed Demand and Future Three Demand (also known as EDI Demand) are used.  These terms are explained below.

·     Projected Demand is the forecasted quantities entered through the Projected Demand Maintenance conversation within the Master Scheduling module or through the Forecasting Interface module.  It includes forecast entered for the part at the detailed item level as well as any forecast entered at the product family level that has been exploded through the planning bill of material.  This projected demand will not be considered for periods prior to the demand fence date.

·     Consumable Demand can consist of those customer orders, transfer orders, transfer requisitions, Synchro offset releases, component requirements, and flow requirements that were anticipated within the projected demand quantities.  Sales orders are also considered as consumable if their Sales Order Planning flag is set to Y (yes).  The Sales Order Planning flag is Y on any order that is sourced from manufacturing inventory, or from distribution inventory at a manufacturing warehouse where the Sales Order Planning flag on the Warehouse Description File is Y.  A consumption code, which is maintained in Part Master Maintenance in the Design Engineering module, determines which of the above types of demand are consumable for an item.  Valid consumption code options are:

0    No demand is consumed

1    Sales orders, transfer orders, transfer requisitions, and Synchro offset releases are consumed

2    Component requirements and flow requirements are consumed

3    All of the above listed in options 1 and 2 are consumed

(Customer orders are maintained in the Order Processing module or in the Inventory Control module if Order Processing is not installed.  Transfer orders and transfer requisitions are maintained in the Transfer Control module.  Synchro offset releases are maintained in the Synchro module.  The Warehouse Description File is maintained in the Design Engineering module.)  Master Scheduling will ignore customer requirements that are to be relieved from distribution warehouses. 

·     Net Demand is calculated by the system as the greater of projected and consumable demand for a period provided the period is after the demand fence date; otherwise, the consumable demand is used.  This process of netting demand ensures that demand is not underestimated.  Further detail on the netting process the system uses is explained in Exhibit B at the end of this section.

·     Unplanned Demand is that demand which comes from unplanned customer orders, transfer orders, or transfer requisitions.  These are orders that were not taken into account when the original forecasts were developed.  Each customer order, transfer order, and transfer requisition has a planned/unplanned code so the planner can indicate to the system those orders coming from unexpected sources.  These orders should therefore be added to rather than netted with projected demand.  (Note that the same considerations apply for unplanned customer orders as planned customer orders—a customer order is only included in the calculation if it is sourced from manufacturing inventory or if it is sourced from distribution inventory at a manufacturing warehouse where the Sales Order Planning flag is Y (yes).  Only transfer orders and requisitions sourced/received into manufacturing inventory in manufacturing warehouses are considered.)

·     Unconsumed Demand refers to the demand that qualifies as consumable demand, but which did not consume forecasted demand because the consumption code was set to 0,1, or 2.  For example, component requirements and flow requirements are considered unconsumed demand when the item's consumption code is equal to 1 (i.e., consume sales orders, transfer orders, transfer requisitions, and Synchro offset releases only).

·     Future Three or EDI Demand is demand passed into MAC-PAC from the Future Three Interface.  This demand is stored as projected demand with a unique demand type.  These unique demand types for EDI demand are stored on Reference File category D26.  This demand is not sales order demand that originates from MAC-PAC's EDI module.

Target Inventory

The planner is provided with two methods of specifying a target inventory policy that is appropriate for each part.

·     The Target Inventory Days/Weeks option on the part master record indicates that the planner wishes to have on-hand at the end of a period enough inventory to satisfy the expected demand for the specified number of days (for daily master scheduled parts) or weeks (for standard master scheduled parts) into the future.

·     The Safety Stock option on the part master record indicates that the planner wishes to have on-hand at the end of a period the specified buffer quantity.

Master Scheduling will propose a schedule that will build up inventory during each planning period such that the target inventory, including the safety stock, will be available at the end of the last week in the planning period.

Suggested Schedule Quantity

Master Scheduling will suggest a production schedule that will meet demand and achieve target inventory requirements, smoothed over the weeks in a planning period.  The schedule is automatically adjusted to satisfy order policy rules.

The detailed logic used in the tentative schedule calculation is illustrated in Exhibit A at the end of this section.

Projected Inventory

For the first week in the master schedule, the system calculates the projected beginning inventory level.  The basic calculation is as follows:

·     The on-hand and planning balances in the manufacturing warehouse,

·     Plus any existing distribution inventory at all distribution warehouses for the plant where the Available for Planning flag is Yes.  (This flag is defined on the Warehouse Description File within Design Engineering.)

·     Minus inventory reserved for customer orders, if any balance types are available for both planning and distribution and if the Sales Order Planning flag on the Warehouse Description File is No,

·     Plus past-due supply (purchase orders and manufacturing orders with due dates prior to the current date),

·     Minus past-due demand (customer orders with promise dates prior to the current date or component requirements with start dates prior to the current date),

·     Minus expected demand (projected demand records, customer orders, delivery requests, and dependent demand),

·     Plus expected supply (calculated from the tentative master schedule file).

Top-Down Scheduling

The demand for a part includes the dependent demand, or the quantity required in the production of a higher-level part.  If the higher-level part is a master scheduled part, Master Scheduling will use the tentative master schedule of the parent to calculate dependent demand.  For this reason, the higher-level parts should be scheduled before the lower-level parts.  The batch process automatically schedules in this top-down sequence.

Planning Periods

The tentative schedule generation process allows three planning period options: weeks, months, or user-defined periods.  The planning period is used in four ways:

1.   Projected demand will be retrieved and accumulated for each planning period.

2.   Consumable demand will be netted against projected demand over a planning period.

3.   Production will be planned such that the target inventory will be available at the end of the last week in a planning period.

4.   The production schedule will be smoothed over a planning period.

A schedule generated using monthly planning periods may differ from one generated using weekly planning periods.  To ensure the most meaningful master schedule, planning periods should be used consistently throughout the system.  More information on planning periods is included in the key concept "Planning Periods."