【正文】 Lead time Continuous Flow Processing dramatically reduces lead time, giving greater responsiveness to the customer. 1 2 3 Batch Production Process 1 2 3 4 5 6 7 8 9 (time in minutes) ?First part plete after 7 minutes ?Customer order plete after 9 minutes delay delay ?First part plete after 3 minutes ?Customer order plete after 5 minutes 7 9 5 C F P Takt time Once material flow has been improved, takt time matches the pace of the manufacturing process to customer demand. Takt Takt time kt tiContinuous Flow Processing P F C Levelled production Pull system ? Calculation ? Application ? Benefits Takt time is the frequency at which a part must be produced to satisfy customer demand: Takt time = total time available* total customer demand Takt time makes no allowances for machine inefficiency (. breakdowns, changeovers). In some cases it may be necessary to allow for inefficiency, but in this case Target Cycle Time is used. Takt time calculation Takt . 9660 minutes per week 1000 units per week = minutes * Only management allowances are deducted: Tea breaks Lunch breaks Team meetings Clean down time There are three main ways to apply takt time: A B C A B C 1. Basis of manpower allocation 2. Performance monitoring 3. Tool and capacity planning T i m e T i m e Operators Operators End of shift report takt Time Plan Actual 67 78 89 910 1011 1112 121 12 Application of takt time Takt Coping with Fluctuating Demand Takt time changes according to customer demand ? Customer demand can vary due to: – seasonal products – poor scheduling or munication ? Constantly changing the takt time can be counter productive ? A realistic promise may be to base takt time on the average customer demand over, say, a month Customer DemandJanuary February March April customer demand Takt time Takt Pull System The Pull System ensures that the right parts are produced and conveyed to the right place at the right time. Continuous Flow Processing P F C Levelled production Takt time Pull system ? Push versus Pull ? Shop stocks ? Kanbans ? Types of Pull Systems Emergency arises Assumptions incorrect Override work to list As these assumptions fail, the system must be overridden to satisfy the customer. Push system Pull ? Assumptions are mad