Saturday, May 5, 2012

Why is repetitive manufacturing treated like a black sheep in the SAP functions family?

Repetitive manufacturing! It has its own menu area in SAP! It's a bit scary to some, a mystery to most. Some people touched it back in the late nineties when it wasn't quite ready yet and some heard this and that about it over the past few years. Most people I have dealt with, do not know why it is there and what it can do. And then there are a lot of people who guess and interpret the functionality in their own way. So please allow me to take a stab at it as well. Unfortunately you can't find much documentation about it. So you will have to do quite a bit of trial and error. Since I am a true believer in RepMan and a convinced advocate (there are probably some folks out there scratching their head and wondering when I will ever give up promoting it - my SAP Mentor shirt reads "Use MF50" on the back) I spent considerable time and effort making it work for my clients. I am not 100% there yet, but my never ending quest continues. Here are some thoughts. You will find more detailed suggestions on how to make it work in some future blogs.

 Misconception about repetitive manufacturing number 1: "since I am a discrete manufacturer I can't use it!" Repetitive manufacturing should not be classified as a third option after discrete and process manufacturing. Discrete manufacturing is roughly everything that after you put it together, you can take it apart again. An automobile, a telephone, a coffee maker. Process manufacturing is, as its name applies, a process to combine and mx ingredients into something you can NOT take apart anymore. Take orange juice, tomato soup or paint. Repetitive manufacturing has nothing to do with that classification but allows you to execute either one in a much more simplified way (no need to convert planned orders or post an individual goods issue for every component). RepMan ist just not good in a job shop environment where every part is different and needs its own order and spec. However, if you have standard parts and you make them again and again using the same instructions in a routing and BoM, you are a repetitive manufacturer. For some reason many people refuse to have their operations classified as a repetitive shop. In one instance the planners of a maker of water faucet filters vehemently defended their position that they don't operate like a repetitive manufacturer. They put through 75,000,000 pieces per day in that one plant alone and have 12 different filters. This is not a blog to point out the advantages those planners would get from using SAPs repetitive manufacturing module. Otherwise I would write another 25 paragraphs on this. 

 Misconception about repetitive manufacturing number 2: "you have to make millions of the same thing every day!" Not true! Wouldn't you say that if you only make one product a day, but it's the same product, you repeat the process? Repetitive manufacturing with SAP allows you to schedule by takt, amongst other things, and that helps you to smooth a production program that suffers from uneven and unpredictable demand. It also allows you to schedule your basic make to stock products and let the make to orders flow in as required. This is very easy in RepMan and very difficult with regular production or process orders. So if you have repeatable products, no matter how small the volume, take advantage of the more efficient transactions. RepMan was developed by SAP coming from the need to plan and execute more efficiently. 

Misconception about repetitive manufacturing number 3: "we can't control our cost with a cost collector!" In RepMan you collect cost on a so-called product cost collector. So you don't need to post cost for every order separately but for the product collectively. If your costing people tell you that that does not work for them, ask them to explain to you why. And don't give up on having the opportunity to save a load of money in producing the right product at the right time in the right quantity at the right place just because someone says "I don't know why, but we need to cost every order separately and we have done so for 50 years.

 Misconception about repetitive manufacturing number 4: " backflush is not an option for us and a must for repetitive manufacturing" First: you do not have to backflush. Second: why not doing it? In my mind there is absolutely no need to have inventory management by the minute. The smallest unit in inventory management, planning or MRP is days. So it should be sufficient if you post a GR for the lines at the end of the day and have the items backflushed accordingly. (there is also reporting point backflush for cycle times in excess of one day)

Misconception about repetitive manufacturing number 5: "repetitive manufacturing only has planned orders. I need production orders" When MRP generates supply elements for products setup for repetitive manufacturing, it creates orders of the type PE (not LA which are planned orders which get turned into production orders). A PE type order does not need to be converted. It's executable right away and it can use a rate routing, a recipe or a standard routing. It may also be immediately scheduled and costed and capacity checked and fixed. It's a beautiful thing and makes your life as a planner much more enjoyable. 

Repetitive Manufacturing excites me (I know, I should get a life) with its simplicity in execution, effectiveness in usability and ability to automate a complex process. It has many features which allow you to practice 'lean' with its line balancing, sequencing board, takt-based scheduling and mixed model planning. It is worth looking into and has been proven to increase visibility into the process, reduce waste in the supply chain (lean) and improve flexibility to customer demand (agile).  "Use MF50!"

6 comments:

  1. Hello,
    do you have any information about co-products. It seems there are some problems when you run the cost collector settlement.
    When you create the cost collector, the sttlement rule is created just to the main co-product. It´s not possible to modify the rule to take into account the relation between co-products.
    How do you do to solve it?
    Thanks in advance

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    1. sorry, but I am not aware of or familiar with this problem...

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  2. First off I would like to say I agree with you on most of your points. What I have been questioned with recently, I am not sure of the best way to answer the how, and that is the inventory piece versus time within the repetitive environment. As an example suppose you have a process where your customer orders are of varying quantities and time while also having longer processing times. Sometime that product sits between two steps up to a day and in order to better manage your inventory you want to implement a cycle counting program. Would a repetitive environment hurt you more because the inventory in process would be lost to the system before it was claimed? This maybe a bigger deal because of longer component lead times and components that are used in multiple finished part. What are your thoughts with regards to a repetitive versus discrete in an environment like my example? Would the benefits to planning and scheduling still out way the potential inventory issues?

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    Replies
    1. Hi there
      on a general note and in my personal opinion, the repetitive environment is much better suited to deal with variability in lead time and wip than discrete. If you want to track wip (inventory between stations) you can use reporting points in the rate routing (I find rate routing very confusing. In germsn this object is called 'Linienplan' which directly translated means 'production line route' nd id the much better descriptive term). If you set up a line hierarchy in RepMan, you can periodically balance the line so that the cycle time on each station is roughly the same. That way you can avoid build up of inventories between stations. This is one option to deal with varying lead and cycle times.

      in a nutshell: if you are in a repetitive environment (you re producing the same products again and again), and most production companies are, you have many more opportunoties to deal with complexity and variability and get your production lines to flow and be lean.

      SAP has developed RepMan because discrete didn't work that well for most, but a lot of people either don't understand it very well or don't know about it alltogether.

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  3. Hi,
    I have been told that one of the disadvantages of using REM is that QM functionality is limited, but I dont know QM very well. Can anyone comment on the limitations regarding the use of QM in REM (if any)? As far as I can see inspection lots can be created at reporting points. I would assume that this provide the functionality to perform quality inspections along the complete production line - even on semi finished products?

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  4. Hi,
    Could you please tell me in Repetitive Manufacturing why WIP is calculated Target Cost as it calculated WIP on Actual cost in Discrete Manufacturing.
    I need information for difference from costing point of view
    Re

    ReplyDelete

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