Overview

Merlin's massively powerful MRP engine can operate at any one of three levels (explained below).  Here is what it does:-

First, it analyses the subassembly requirements for all top-level jobs within the scope selected (to an infinite number of levels deep) and provides various report analysis options including Mission Impossible warnings.

Next it will raise Internal Works Orders and then Production Jobs to meet the subassembly requirements (if necessary), and schedule completion of these jobs in sequence so that each in turn is ready for the for the calling job(s) on the correct date(s).

When this process is complete (or if no subassembly shortages were found) Merlin will analyse all top-level jobs and associated subassembly jobs within the scope, and provide a similar set of report options relating to materials shortages, if any.

Next, it will raise Purchase Orders to remedy the materials shortages, if any, and then allocate materials to all of these jobs.

Finally, you have the option to Run Schedules which will calculate (or recalculate, if Delivery Schedules already exist) and print Delivery Schedules for all of your suppliers* so that materials are called-off as and when required, with one drop per month from each supplier on the earliest date within each month on which any item from that supplier is required.

* Suppliers and materials must have scheduling enabled on the respective record cards in order to be included in this routine.

In a matter of minutes you can complete a task that could take days to figure out and set up manually!

Scope

The Merlin MRP Engine can operate in any one of  three modes according to the scope you require:  Single Job, or Job Series, or All Outstanding.  To run the MRP process for a single job, please see [Manufacturing / Shop Floor Control / Run MRP].

Please note: you manually create Sales Orders for the top level assembly only, and Authorise these to create Active Jobs when you want them to go into production  Each activate job should be included in an MRP run at one of the three levels, so that Merlin can create jobs for any required subassemblies.  You may wish to organise your jobs into groups (Job Series) based on perhaps week number or calendar month and run the MRP process for each group at the appropriate time.

If you wish to build subassemblies to place in stock, create top-level Sales Orders for these with "HOUSE" as the customer, and Authorise these for production.

Using the MRP Engine

Subassembly Processing

When you Run MRP from Buying Office, it will give you the option of running in one of two modes.  Selecting All Top Level Jobs will set the scope to All Outstanding, which is to say all top-level jobs (whether in a Job Series or not) that have not yet been processed by the
Merlin MRP Engine.  Alternatively, you can restrict the scope to a nominated Job Series. 

(You can assign a Series Number to any job(s) in Admin / Sales Orders & Jobs.  You enter a common Series Number (or name) to a range of jobs that you want linked as a Buying Group - perhaps placing all of the jobs starting in any week or month in its own series, such as [2001MAY],or whatever suits you.) 

It is important to work in a methodical way and remember that once you have launched the MRP Engine you should allow it to complete the processing routines.  If you have reason to abort the process part way through (say to fix a problem) and the EXIT button is inactive, you can leave the process by clicking the X button at the top right corner of the screen.

However, if you wish to be able to resume at a later time from the point at which you aborted, you should ensure that you stop the process at one of the following stages:-

1. Before generating Internal Works Orders for subassemblies

2. After AutoGenerating subassembly jobs for Internal Works Orders

3. After you have generated Purchase Orders for materials

4. After running AutoScheduling

Each job that has been fully processed will be flagged and locked out of future runs to avoid multiple processing.  However, AutoScheduling always has the scope of all outstanding Purchase Orders.

When you launch Run MRP you will be prompted to set the scope.

All Top Level Jobs is the default, and to select this mode just click OK.
To select Job Series Only mode, click the radio button beside this option.  The drop-down combo will then become active, and you can use it to select the Job Series you wish to process.  When you are happy with your selection click OK.

Please note that once you have selected Job Series Only mode, the OK button will not be active until you have selected a Job Series from the drop-down list.  To activate the button, either select a Job Series, or click the All Top Level Jobs radio button.

Job Series Mode will not be active if no outstanding Job Series items are present (i.e. none exist or all have been processed).

Once you have made your selection you will see an almost blank screen, with just a simple control panel at the bottom left.  The top information panel will confirm the mode you have selected.  If you have made a mistake, bust click EXIT and start again.

Otherwise,  click the PROCEED button and await the magic.
Merlin will do a lot of analysis and calculation, which, depending upon the size of your database and the speed of your PC, might take a few minutes.  The screen will then take on the appearance shown below.

Important: Merlin will warn you every time it has drilled down 50 levels, and give you the opportunity to cancel the process.  If your BoMs are this deep, just click to continue.  Otherwise Stop the process and check your BoMs for repetition of a higher level subassembly within a lower level BoM.

The three buttons to the left of the Subassembly Processing panel offer various report headers, with sub-options that will be presented where appropriate when you click to make a selection.  Just choose logically those reports you want you want from what is offered, and whether you want to view on screen or to print them.

Please note: when studying the days-error on a report, positive figures indicate a problem (the number of days error - Mission Impossible) whereas negative figures indicate the number of days in hand over and above the required build-time.

When you have all the information you want from this section, click DONE.  The Subassembly Control Panel will then update as below:-

The only buttons active at this point are AutoCreate Works Orders and QUIT.
Clicking the former will offer you a list of proposed Internal Works Orders for required subassembly creation.  You will then be asked if you want Merlin to generate these Works Orders for you.  Naturally, if you see a problem, click QUIT and fix it.  Otherwise, accept the offer.

When you have OK'd the printed Internal Works Orders, you will see the AutoCreate Jobs button has come alive.  Clicking this will do as it says - automatically create a production job for each Internal Works Order that was generated.  Various reports and options will be offered along the way.
Do not skip this step unless you wish to create the subassembly jobs manually!

Once you have completed these processes,  the subassembly side of things is taken care of.

It is desirable that you print, rather than view on screen, the list of AutoCreated Jobs, because you will need to go to Manager/Job Manager to amend the Shop Floor Schedule
if you are using this feature and you wish to change the default sequence at job level, or set scheduled start and finish dates for each process (please see Admin / Sales Orders & Jobs  and Job Authorisation).

Important Notes

If Production Batch Quantities have been set for any assemblies on their Resource Record Cards, the Works Orders (and subassembly jobs) for these items will be generated only in multiples of the batch, even if the whole batch is not required.

However, if there are repetitions of the same subassembly, any quantities over-called because of the batch setting will be credited to the next encountered requirement.  If this does not satisfy the requirement, a further Works Order will be generated at the batch quantity, or a multiple thereof.

It should be further noted that if Works Orders already exist for non-batch quantities (i.e. created before a batch was specified or modified on the assembly Resource Record Card), over-production is likely to result because Merlin cannot resolve these to exact batches when crediting them against current requirements.  You may therefore wish to complete or stop these production items before running the MRP process.

Materials Processing

Once the Subassembly Processing is complete, the  CONTINUE button will be active, and clicking this will start a similar analysis running for the raw materials and piece parts; an equivalent sequence of command buttons will appear in the Materials Processing control panel to the right of the screen.

Follow similar steps to the above to generate reports, proposed purchase list, and Purchase Orders.  Merlin will then Allocate Materials to all of the top-level jobs and subassembly jobs AutoCreated in the process.

At this point you can click the button to generate Delivery Schedules (where permitted -
please see Resource Record Cards and Business Contacts Record Cards) for your suppliers, based on the run times for your jobs, and lead times for the various materials, rewriting any existing Delivery Schedules.

Please note:  Delivery Schedules have a blank header area so that you can use your company headed paper.

And that is really just about it.  So little effort for such a big job!

The skill in using this tool is timing - working it into your strategy in a logical way.  Every new job you add to your production schedule will alter the sequence of requirements and deliveries, and you may not wish to lay this upon your suppliers on a daily basis!  On the other hand, you can't leave things until it's too late, either.  Only you can decide the appropriate game-plan in your organisation.

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