Calculation static key figures |
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In this chapter all formulas used in the application for static key figures are listed and described
Contents
1.3 Daily demand (DD, Customer)
1.4 Directional stability (DS)
1.5 EPEI (Every Part Every Interval)
1.9 Tact time (TTOT , Customer)
1.10 Tact time 24hrs (TT24 , Customer)
2.1 Static flow grade (Time line)
2.2 Throughput time clocked process object
2.3 Throughput time inventory push object
2.4 Throughput time lead process object
2.5 Throughput time process object (general type)
2.6 Throughput time storage object (Supermarket, Inventory)
2.7 Throughput time transport objects (FIFO, internal and external Transport)
formula |
Description |
\[ CT_{Process} = CT_{i} \] |
CTi: Cycle time per product |
formula |
Description |
\[ CT_{Station}=CT_{pm} \times Ns \] |
CTpm: Cycle time per product for process multiple object Ns: Number of processing stations within process multiple object |
1.3 Daily demand (DD, Customer)
formula |
Description |
\[ DD_{d}=\sum\limits_{p=1}^{\#P} DQ_{P}\: \mathrm{per}\ [s] \times WorkingTimeShiftModel \frac{[s]}{[d]} \] |
#P: Number of products per customer object DQ: Demand quantity per product and second WorkingTimeShiftModel: Working time at the reference day within the shift model as number of seconds minus pauses and unplanned portions |
1.4 Directional stability (DS)
formula |
Description |
\[DS=\frac{\#IO - (\#Rework + \#Scrap)}{TotalParts} \] |
Total parts: total portion of 100 parts #Rework: Number of rework parts, with: Rework rate * 100 #Scrap: Number of scrap parts, with: Scrap rate * 100 #IO: Number of IO parts, with: TotalParts - #Rework - #Scrap Average over all products per process object |
1.5 EPEI (Every Part Every Interval)
formula |
Description |
\[ EPEI_{Process}=\frac{\sum WorkingTimes[s]+\sum SetupTimes [s]}{\#ParallelStations \times (Availability/100 \times WorkingTime[s/d]} \] |
Sum of working times: Sum of all working times, incl. general rework: \( \sum\limits_{1}^{\#P} =LotSize_{p} \times CycleTime_{p} \times (1+\frac{ReworkRate_{p}}{100}) \) #P: Number of products per process Sum of setup times: \( \sum\limits_{1}^{\#P} = SetupTime_{Process} \) If setup time matrix is applied, mean value over all setup times is used for setup time of object |
formula |
Description |
Operating time (OT) |
Working time on the reference day within the shift model as the number of seconds minus breaks and unscheduled parts. If no shift model is defined: Default: 24 hours (84,600s) |
formula |
Description |
\[ TT_{Object}=\frac{86400\frac{[s]}{[d]}}{DD_{d}} \] |
DDd as daily demand of all products per day and customer object: \( DD_{d}=\sum\limits_{P=1}^{\#P} DQ_{P} \: \mathrm{per}[s] \times WorkingTimeShiftModel \) #P: Number of products per customer object DQ: Demand quantity per product and second WorkingTimeShiftModel: Working time at the reference day within the shift model as number of seconds minus pauses and unplanned portions |
formula |
Description |
\[ TT_{ProcessObject}=\frac{86400\frac{[s]}{[d]}}{DD_{d, avg}} \] |
DDd,avg as daily demand over all products per day and all customer objects: \( DD_{d, avg}=\sum\limits_{K=1}^{\#K} DD_{d,C} / \#C \) #C: Number of customer objects DDd,C: Daily demand per Customer object (see tact time for customer) |
1.9 Tact time (TTOT , Customer)
formula |
Description |
\[ TT_{OT}= \frac{WorkingTimeShiftModel\frac{[s]}{[d]}}{DD_{d}} \] |
DDd as daily demand of all products per day and customer object: WorkingTimeShiftModel: Working time at the reference day within the shift model as number of seconds minus pauses and unplanned portions |
1.10 Tact time 24hrs (TT24 , Customer)
formula |
Description |
\[ TT_{24} = \frac{86400\frac{[s]}{[d]}}{DD_{d}} \] |
DDd as daily demand of all products per day and customer object |
2.1 Static flow grade (Time line)
formula |
Description |
\[ FG_{static}=\frac{\sum valueAddingTime + \sum nonValueAddingTime}{\sum valueAddingTime} \] |
valueAdding and nonValueAdding times from sums of partial throughput times Due to division through total throughput time, result always >= 1 |
2.2 Throughput time clocked process object
formula |
Description |
\[ TGT_{ProcessClocked}=\frac{\sum\nolimits_{i=1}^{\#P} (CT_{i}\times \#S + CT_{i}\times(TQ_{i}-1))}{\#P} \] |
#P: Number of products per process CTi: Cycle time per product #S: Number of stations per process object TQi: Transfer quantity per product i Based process parametrization added to either value-adding or non-value-adding throughput time |
2.3 Throughput time inventory push object
formula |
Description |
\[ TGT_{InventoryPush}=\frac{\sum\nolimits_{i=1}^{\#P} T_{i}}{\#P} \] |
#P: Number of products per object Ti: Minimum dwell time per product |
2.4 Throughput time lead process object
formula |
Description |
\[ TGT_{ProcessLead}=\frac{\sum\nolimits_{i=1}^{\#P} (TGT_{i}+CT_{i}\times(TQ_{i}-1))}{\#P} \] |
#P: Number of products per process TGTi: Throughput time per product CTi: Cycle time per product TQi: Transfer quantity per product i Based on process parametrization added to either value-adding or non-value-adding throughput time |
2.5 Throughput time process object (general type)
formula |
Description |
\[ TGT_{Process}=\frac{\sum\nolimits_{i=1}^{\#P} (CT_{i}\times TQ_{i})}{\#P} \] |
#P: Number of products per process CTi: Cycle time per product TQi: Transfer quantity per product i Based on process parametrization added to either value-adding or non-value-adding throughput time |
2.6 Throughput time storage object (Supermarket, Inventory)
formula |
Description |
\[ TGT_{Storage}= TT_{avg}\times \sum\limits_{i=1}^{\#P} I_{i}+DelayTimeBeforeStorage \] |
TTavg: average customer tact time for all customer objects #P: Number of products per process I: Initial inventory per product Added to non-value-adding throughput time |
2.7 Throughput time transport objects (FIFO, internal and external Transport)
formula |
Description |
\[ TGT_{Transport}=TransportTime \] |
TransportTime for external transports only with one-way time Added to non-value-adding throughput time |
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