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Training - MRP Generation

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In this task your planners and buyers will make a full MRP run to generate an initial set of jobs and POs.  

Education:

Gude   MRP Guide - Phase 3 - Generate Jobs and POs  

Screen_Help   Screen Help - MRP

Video_Link Time to Shipment MRP Screenshot Series

 

MRP Guidelines Videos:

Introduction

P Item Lead Days

M Item Job Days

Item Order Policy

Time to Shipment Target

Long Lead Days Purchasing

SO Required Date

Daily MRP Generation

PO Price Verification

Late PO Expediting

Job Release

 

Video_Link Video - Using MRP Analysis Codes

Training Tasks:

Generate a complete MRP session all the way through PO conversion.  

Review the results in the Job Schedule and PO Schedule screens.  

Ignore late dates  

You may see some late dates during MRP generation or in the master schedule due to existing sales orders, jobs, and POs in the sample date, which were created well before the current date.  Ignore any such late dates for training purposes.    

MRP Guidelines

Time to Shipment MRP only works properly when used according to the following guidelines:

1. All P items require a standard Lead Days for procurement time    

Without exception, all P items require a standard Lead Days for expected procurement time.  The standard Lead Days establishes PO due dates, lead time contribution to higher-level items, and item planning periods, and also enables late PO tracking.  For all these reasons, a realistic value is required that is not padded or artificially inflated.  

Never pad or inflate standard Lead Days  

Never pad or inflate the standard Lead Days because whenever an item has a To Order policy, its Lead Days contributes to the lead times of higher level items and progressively magnifies lead times at each higher level, resulting in severely distorted Time to Shipment targets.  

2. All M items require a standard Job Days for production time    

Without exception, all M items require a standard Job Days for expected production time.  The standard Job Days establishes job start and finish dates, lead time contribution to higher level items and time to shipment, and item planning periods, and also enables late job tracking.  For all these reasons, a realistic value is required that is not padded or artificially inflated.    

Never pad or inflate standard Job Days

Never pad or inflate the standard Job Days because whenever an item has a To Order policy, its Job Days contributes to the lead times of higher level items or to its own Time to Shipment target.  

3. All items require a standard Order Policy      

Without exception, all items require a clear and consistent Order Policy to determine planning intent and lead time contribution.  When you assign an item a To Order policy, your intent is to always buy or make the item to order.  You do not expect stock to be on hand and therefore the item's lead time contributes to the lead times of higher-level items or to its own time to shipment target.  When you assign an item a Demand Driven or Manual Reorder Point order policy, your intent is to always maintain stock on hand for immediate use in Jobs and SOs. You expect stock to be available for the majority of likely demand scenarios and therefore the item is not a lead time contributor.

The Order Policy must reflect your actual planning behavior

If you buy or make an item to order in actual practice, it must be assigned a To Order policy so that its lead time properly contributes to the lead time of higher-level items or to its own time to shipment.  If you stock an item in actual practice, you must assign the item a Demand Driven or Manual Reorder Point order policy so that its lead time does not erroneously contribute and distort the lead times of higher-level items or its own time to shipment.  

Avoid CTO job linking with standard items  

When a top level M item is flagged for CTO job linking it is assigned a To Order policy and jobs are linked to and generated directly from sales order lines for the exact quantity ordered.  CTO linking is ideally suited for one-off, custom items that are made to order and never stocked.  For standard items, however, CTO linking is counter-productive and should be avoided because such items are interchangeable from order to order and subject to stocking.  There is no ability to adjust CTO jobs to account for stock on hand or to consolidate demand into more efficient job sizes.  Furthermore, CTO linking forces items to be made to order, even in cases where items with frequent orders could be planned with a Demand Driven order policy to enable immediate shipment from stock.

4. Refine Time to Shipment targets to reflect your marketing objectives  

Time to Shipment targets are calculated for all top level M items to establish sales order required dates.  Each item's Time to Shipment target is derived from the standard lead times and order policies of the item itself and lower level lead time contributors.  All Time to Shipment targets must be refined as needed until they reflect your marketing objectives. Time to Shipment can be eliminated altogether by assigning the top level item a Demand Driven stocking order policy. Time to Shipment can be reduced with strategic Demand Driven Stocking order policy assignment to key components to remove them as contributors to the item's pre-job Lead Days, and by tightening the item's standard Job Days over time as you get more efficient in the shop.  

5. Replace blanket POs with a supply pipeline  

If you are using blanket POs with a set of scheduled deliveries, each such item should be assigned the Demand Driven order policy and the blanket purchase order should be replaced with a supply pipeline so that future POs are generated by MRP.  Blanket POs are counter-productive because they require constant adjustments to avoid shortages and over-stocking when scheduled supply inevitably differs from actual demand.  By contrast, MRP generates demand-driven purchase orders at self-adjusting intervals.    

6. Purchase long lead time items with a supply pipeline

Assign the Demand Driven order policy to P items with long lead times.  The monthly Potential Demand rate and Supply Days interval calculate a Reorder Point and Min Order quantity that generate a supply pipeline of overlapping POs, each due to arrive at staggered intervals.  A demand-driven PO pipeline is far more efficient than large and infrequent POs because more frequent replenishment eliminates the risk of lengthy shortages and excessive stock on hand.  

7. Always leave the SO line Required Date as is for current orders    

The sales order line item Required Date is established by the item's Time to Shipment target.  Always leave the Required Date as is fpr current orders because it is an internal MRP date that is aligned with dependent job dates and provides consistent shipping priority relative to other orders.  Never use the Required Date as a "wish date" by salespeople and never move the date out when it is past due.  The only time the date should be manually changed is to enter a blanket order where the customer requests a set of future quantities and ship dates.

Use the Expected Ship date for customer communications  

The line item Required Date is accompanied by the Expected Ship date, which is an external date used for customer communications.  The Expected Ship date can be freely adjusted to reflect late trending jobs, shipping preparation time, or other factors that may cause the actual ship date to differ from the Time to Shipment target.  

8. Generate MRP on a daily basis to full completion

For just in time manufacturing it is essential to generate MRP on a daily basis to full completion.  Daily job and PO generation enables MRP to respond immediately to new sales order demand or existing demand that falls into item planning period action windows.  Daily generation also prevents misalignment of job and PO dates with required dates.  Complete each MRP session in full by converting all planned jobs at all levels and all planned POs to ensure complete demand profiles and date alignments.  Always generate and convert jobs and POs in the same session, even when jobs are converted by one person and POs by another.  

Never create future jobs  

All jobs are generated through MRP in response to current net demand within item planning period action windows.  Never enter future jobs for any reason because they conflict with the demand-driven architecture of the master schedule.  In contrast to current demand, which is firmly set, future demand is tentative and subject to date changes, quantity changes, cancellations, and specifications changes that adversely affect interdependent items at lower levels.  Instead of future jobs, you can enter sales orders with future required dates, as with blanket orders, and then MRP will only respond to current demand when required dates eventually fall into item planning period action windows.  

9. Verify and update supplier prices before PO conversion  

To ensure the integrity of the costing system, always verify and update supplier prices before converting planned POs.  The planned POs screen within MRP is optimized for pricing maintenance with the ability to create and update supplier price records and present review notes for special pricing instructions.  The costing system depends on realistic PO prices because when a purchased item is received, its inventory cost is updated by the PO cost and is the cost basis for subsequent job issue transactions.  The PO invoicing process often occurs well after actual receipt and has no retroactive effect on receipt costs or inventory costs.  

10. Expedite late POs on a daily basis

Monitor late POs on a daily basis in the PO Schedule screen and contact suppliers to expedite delivery so that dependent jobs can be released to production without delays to planned start dates.      

11. Release jobs only when materials are fully allocated

Release jobs to live production in the Release Jobs screen only when materials are fully allocated.  The job release process is a vital MRP function that serves two purposes.  First, materials are allocated to jobs in planned start date order so that jobs are started in the correct order of multi-level assembly.  Second, released jobs are rescheduled with new finish dates relative to their actual release date, which automatically updates the job schedule to reflect work in process.