introducing-flow-part-ii-balancing-a-repetitive-line.pdf

Generated by Jive on 2015-02-06+01:001

SAP ERP Manufacturing - ProductionPlanning (SAP PP): Introducing Flow, PartII Balancing a Repetitive Line

Posted by Uwe Goehring Dec 11, 2014When youre in the business of manufacturing parts that you sell through a catalogue, chancesare youre a repetitive manufacturer. And if you produce the same product over and over ona mixed model line, SAP has great functionality for you to schedule and level your productionplan readily available in ECC 6.0. No need for extensive customizing or running a project with 5consultants over the next 6 months; just yesterday I configured a demo into a clients sandboxsystem within 3 hours.As we discussed in part I, to introduce flow into the production line means reducing WiP andwith it cycle times. So flow is very desirable, especially if youre in the repetitive business andto achieve it, you need to balance the operations of the line. Balancing the line means that youallow the same amount of time a product can spend on a work center for every operation. In thatcase there will be no buildup of WiP (no product has to wait until it can processed on the nextwork center) in front of any work center.Lets see how SAP-ERP can help you do that: First you need to set up your products for repetitivemanufacturing and create at least one production version through which you assign the productsto the Line Hierarchy. This represents your mixed model line. The production version relatesto a routing that contains all operations and work stations the product undergoes while beingproduced (it flows through the line).The routing may be a Rate (Line) Routing that can be represented graphically

SAP ERP Manufacturing - Production Planning (SAP PP): Introducing Flow, Part II Balancing aRepetitive Line


and has all the details necessary for lean production.



Once all products are assigned to the Line Hierarchy, you can create a Line Balance for a shortterm planning horizon of, lets say, 4 weeks. In that Line Balance, you copy the demand forthe next 4 weeks and calculate a takt time by which you need to run the model mix to fulfillexactly that demand. This works in the following way: The system looks at the total demand forall products in the model mix for the next 4 weeks and calculates a daily rate for the model mix,which is necessary to meet the total demand over 4 weeks. Imagine you have 3 products - A, Band C and a demand of 200, 400 and 100 pieces over the next week for these products. If thereare 20 working days in your next 4 weeks, you need to produce 10 As, 20 Bs and 5 Cs every dayto fulfill the demand over the next 4 weeks (according to EPEI heijunka leveling). Therefore youneed to produce 35 pieces on the line every day. If you have 7 hours available every day, youneed to produce 5 pieces per hour or introduce a piece into the line every 12 minutes this iscalled the takt time. That, in turn, means that every work center has 12 minutes of work contentbefore it needs to move the product to the next work center.

In above example we have a maximum rate of 35 pieces per 7 hours and a model mix thatadheres to the maximum rate. Now we have to make sure that all operations in any work center



do not exceed the maximum allowable time in any work center the takt time. That, in essence,is Line Balancing and may be carried out graphically in standard SAP.

In the Line Balance we can see that product 188 causes a takt violation with operation 0080 onwork center 65030TRY (note that work station 65030TRY has more work content available. Thisis because we have more capacities available either more labor or more machine capacity). Youcould now do either one of two things: either you increase the amount of machines used on workcenter 65030TRY or you could move the operation to another work center, in the flow, that hasmore work content available. Either way the takt violation is cured.In any case, you have now calculated a takt time the speed by which the line must be run tomeet demand and you can now use takt-based scheduling to determine the sequence plan asfollows.



From here we can now perform a collective availability check, print the daily schedule or fill aheijunka board on the shop floor. The schedule may also be connected with a Kanban controlcycle but that is stuff for another blog post414 Views Tags: sequencing, heijunka, repetitive_manufacturing, repetitive_manufacturing;,takt_based_scheduling

Aditya SDec 13, 2014 7:11 PMHi Uwe,

Thanks a lot for sharing ur knowledge. It will helps a lot to all. Thanks again for ur efforts.

Documents

introducing-flow-part-ii-balancing-a-repetitive-line.pdf