Formulae Aggregate Planning
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- Value Added Throughput Efficiency (VATE) : VATE = Value-added work content Throughput time Balancing Loss
- Where: Idle Time
- Number of Stages
| Little’s Law
Little’s Law: WIP = R x T Throughput (R): is the average number of entities/items completed per unit time, the output rate from a process. Flow time or Cycle time (T): is the average time it takes to complete one cycle of a process. Cycle time = Processing time + Delay time Work in Progress (WIP): is defined as products (or people) which the organisation has partially processed and are not completed. Throughput Time: is the average time required to complete a batch or job. Work Content: is the average time to process one item. Server: is the person or machine doing the work Throughput Time = WIP x Cycle Time WIP = Throughput Time Cycle Time Cycle Time = Throughput Time Work in progress Servers Required = Work Content Cycle Time Efficiency = Amount of product produced x 100 % Amount of raw material used. Utilisation (U) = Resources Used Resources Available Utilisation (U) = Demand Rate (Service Rate x Number of Servers) Cycle time = Process time (for a batch) Number processed Throughput efficiency = Work content Throughput time Value Added Throughput Efficiency (VATE): VATE = Value-added work content Throughput time Balancing Loss Idle Time on each stage = Bottleneck time – processing time for that stage Total Idle time for a process = ∑(Idle Time on each stage) Balancing Loss = Total Idle time for a process Cycle Time x No of Stages Where: Idle Time is when a machine is not processing an item and is waiting for work to be passed from the previous machine in a process. The Cycle Time is governed by the bottleneck in the process. The cycle time will include some idle time on some machines or processes but not the bottleneck. The Number of Stages is the number of separate processes (e.g. number of machines) in the overall production process. Productivity Productivity = Quantity of Output Quantity of Input Productivity = Output from the operation Input to the operation Single factor productivity = Output from the operation One input to the operation Multifactor productivity = Output from the operation All inputs to the operation Actual Productivity = Actual Output Resources actually consumed Total Productivity = Total Output Total Input Download 27.67 Kb. Share with your friends:
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