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1 Piece Flow (a.k.a. Single Piece Flow)
for Lean Manufacturing

Page Contents


1.         What is it?


            a.         Single piece flow is the ideal state where parts are manufactured one at a time, and flow throughout the manufacturing and supply chain as single unit, transferred as customerís order.


            b.         Manufacturing large batches of parts simultaneously, or accumulating parts in a bin for shipping or transferring 2 or more parts at the same time is opposite or contrasted to the definition of Single Piece Flow.


            c.         Single Piece Flow (SPF) supports Just-in-Time, Toyota Production Systems, Lean Manufacturing, Theory of Constraints (Drum, Buffer, Rope), and similar types of philosophies and systems


2.         How Does it Work ?


            a.         Batch sizes are recorded for historical system (baseline).


            b.         Optimum batch size and transfer sizes are calculated, starting with:


                        i.         The most critical work centres

                        ii.        The largest inventory carrying costs

                        iii.       The highest risk processes

                        iv.       The most unpredictable process

                        v.         Other controlling factors


            c.         Action is taken for improvement at the work centres, rules, methods that have the greatest impact on the throughput, customer satisfaction, risk, cost, or inventory carrying charges. These actions can include:


                        i.         SMED

                        ii.        Kanban

                        iii.       Process re-design

                        iv.       Production sequence

                        v.        JIT

                        vi.       Etc.


3.         Resources Required

            a.         Process Map

            b.         Calculator

            c.         Process comprehension

            d.         Value mapping

            e.         Authority to make process improvements

            f.         Process operating date (ie. flows, batch sizes, inventory, etc.)

            g.         Lean process understanding


4.         Symptoms indicating that it is needed


            a.         Long delivery lead times (customers will consider paying more to defeat them)

            b.         Obsolete inventories

            c.         Large batches of defects & rework, all with the same or similar defect.

            d.         High product velocity ratios (3 is excellent, 60 is poor)

            e.         Low inventory turns (100 is excellent, 3 is poor)

            f.         Slow changeovers

            g.         Left-overs at beginning & end of production run


5.         Example/Case Study


            a.         Penny Lane game


Penny Lane Game


1 Start


2 3 4 5 6 7 Done


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