documentation

(001) Actual Advanced Task Completion Rate =MIN(Cap To be Allocated to Adv Tasks,ind adv comp rate)

Units: tasks/Month

Actual Completion Rate of Advanced Tasks. All the capacity available for advanced work is allocated to the new work rate. So, the advanced new work rate is the indicated advanced completion rate or whatever capacity is available to advanced work.

(002) Actual Advanced Task Completion Rate 0 =MIN(Cap To be Allocated to Adv Tasks 0,ind adv comp rate 0)

Units: tasks/Month

(003) Actual Current Task Completion Rate = MIN(Engineering Capacity,ind curr comp rate)

Units: tasks/Month

Actual Completion Rate of New Current Tasks. If there is a need all the available capacity is allocated. The completion of new work has priority over all other tasks. However, to ensure that only work gets done if there is work to do, the flow is protected by a Min function.

(004) Actual Current Task Completion Rate 0= MIN(Engineering Capacity,ind curr comp rate 0)

Units: tasks/Month

(005) Actual Current Task Rework Rate= MIN(Engineering Capacity-Actual Current Task Completion Rate,ind curr rework rate) * Design Freeze

Units: tasks/Month

Actual Current Task Rework Rate is equal to the minimum of either the indicated current rework rate or whatever capacity is remaining after doing the current new work. The MIN-function is to ensure that the rework rate is a reasonable value. The design freeze switch is multiplied to represent when no more rework is done. So, when design freeze takes effect, the designs which failed testing are not reworked and only the designs that pass testing are considered to be completed tasks.

(006) Actual Current Task Rework Rate 0=MIN(Engineering Capacity-Actual Current Task Completion Rate 0,ind curr rework rate 0) * Design Freeze

Units: tasks/Month

(007) Additional Fraction of Methodology Introduced=

Units: dimensionless

The Additional Fraction of Methodology Introduced is the additional percentage of Methodology introduced into the advanced work. This represents the percent of the total tool set available to the organization. Here, keep in mind the base methodology introduced is 0.25. The introduction of a new set of tools means that the set of up-front activities is increased. The cost of introducing new tools is captured by the fact that the up-front activities require more resources.

(008) Adv Task Comp Last Yr 1= INTEG (Inc in Adv Comp Last Yr 1-Incr In Adv Com Two Yrs prior 1,New Advanced Tasks Per Yr)

Units: tasks

This stock represents the recent fraction of advanced tasks completed using the methodology. The delay represents the time required to learn how to use the new tools.

(009) Adv Task Comp Last Yr 1 0= INTEG (Inc in Adv Comp Last Yr 1 0-Incr In Adv Com Two Yrs prior 1 0,New Advanced Tasks Per Yr 0)

Units: tasks

This is the delay representing Learning of the new tool set.

(010) Adv Task Comp Last Yr 2= INTEG (Inc in Adv Comp Last Yr 2-Incr In Adv Com Two Yrs prior 2,New Advanced Tasks Per Yr)

Units: tasks

This stock represents the recent fraction of advanced tasks completed using the methodology. The delay represents the time required to gain experience with the new tools.

(011) Adv Task Comp Last Yr 2 0= INTEG (Inc in Adv Comp Last Yr 2 0-Incr In Adv Com Two Yrs prior 2 0,New Advanced Tasks Per Yr 0)

Units: tasks

This is the delay representing Experience with the new tool set.

(012) Advanced Completed Flushed = IF THEN ELSE(Months to Introduction Date=12,Advanced Tasks Completed/TIME STEP,0)

Units: tasks/Month

Advanced Tasks Completed is pulsed out at the end of the model year. A memory stock, "Adv Task Comp Last Yr", is used to keep track of the advanced tasks completed the previous year.

(013) Advanced Completed Flushed 0 = IF THEN ELSE(Months to Introduction Date=12,Advanced Tasks Completed 0/TIME STEP,0)

Units: tasks/Month

Advanced Tasks Completed is pulsed out at the end of the model year. A memory stock, "Adv Task Comp Last Yr", is used to keep track of the advanced tasks completed the previous year.

(014) Advanced Not Completed Flushed = IF THEN ELSE(Months to Introduction Date=12,Advanced Tasks Not Completed/TIME STEP,0)

Units: tasks/Month

The stock of Advanced Tasks yet to be Completed is flushed out when month to job one equals 12.

(015) Advanced Not Completed Flushed 0 = IF THEN ELSE(Months to Introduction Date=12,Advanced Tasks Not Completed 0/TIME STEP,0)

Units: tasks/Month

The stock of Advanced Tasks yet to be Completed is flushed out when month to job one equals 12.

(016) Advanced Task Completion Rate= IF THEN ELSE(Months to Introduction Date=12,0,Actual Advanced Task Completion Rate)

Units: tasks/Month

This is the rate of Advanced Tasks being completed. This rate depends on the Actual Advanced Completion Rate calculated in the Capacity Allocation Sector. The if-then-else formulation is used to turn off the flow at the instant of the cycle's end.

(017) Advanced Task Completion Rate 0= IF THEN ELSE(Months to Introduction Date=12,0,Actual Advanced Task Completion Rate 0)

Units: tasks/Month

(018) Advanced Tasks Completed= INTEG (Advanced Task Completion Rate-Advanced Completed Flushed, New Advanced Tasks Per Yr)

Units: tasks

Advanced Tasks Completed accumulates when advanced tasks are completed. This stock is flushed at the time of launch to reset for another model year cycle.

(019) Advanced Tasks Completed 0= INTEG (Advanced Task Completion Rate 0-Advanced Completed Flushed 0,New Advanced Tasks Per Yr 0)

Units: tasks

Advanced Tasks Completed accumulates when advanced tasks are completed. This stock is flushed at the time of launch to reset for another model year cycle.

(020) Advanced Tasks Introduced= IF THEN ELSE(Months to Introduction Date=12,New Advanced Tasks Per Yr/TIME STEP,0)

Units: tasks/Month

Advanced Task Introducded Into Development. When there are 12 months to job one, New Advanced Tasks Per Year is pulsed in.

(021) Advanced Tasks Introduced 0= IF THEN ELSE(Months to Introduction Date=12,New Advanced Tasks Per Yr 0/TIME STEP,0)

Units: tasks/Month

Advanced Task Introducded Into Development. When there are 12 months to job one, New Advanced Tasks Per Year is pulsed in.

(022) Advanced Tasks Not Completed= INTEG (+Advanced Tasks Introduced-Advanced Not Completed Flushed-Advanced Task Completion Rate,0)

Units: tasks

Advanced Development Tasks that have yet to be completed. When months to job one equals 12, new tasks are introduced all at once and what is still left of the stock is emptied to reset for another model year.

(023) Advanced Tasks Not Completed 0= INTEG (+Advanced Tasks Introduced 0-Advanced Not Completed Flushed 0-Advanced Task Completion Rate 0,0)

Units: tasks

(024) Base Chng Rate=

1500

Units: tasks

The Base Change Rate is the basic number of tasks that are introduced each year into the product development process.

(025) Cap To be Allocated to Adv Tasks= MAx(Engineering Capacity-(Actual Current Task Completion Rate+Actual Current Task Rework Rate),0)

Units: tasks/Month

Development Capacity for Advanced Tasks can be allocated if there is excess engineering capacity. This represents that the advanced tasks are done only after the current work is done.

(026) Cap To be Allocated to Adv Tasks 0= MAx(Engineering Capacity-(Actual Current Task Completion Rate 0+Actual Current Task Rework Rate 0),0)

Units: tasks/Month

Development Capacity for Advanced Tasks can be allocated if there is excess engineering capacity. This represents that the advanced tasks are done only after the current work is done.

(027) Change in Frac Tasks Comp in Previous Phase=

IF THEN ELSE(Months to Introduction Date=12,Fraction of Advanced Task Completed this Model Year/TIME STEP,0)

Units: 1/Month

The Fraction of Advanced Tasks Completed at the end of the model year is kept in a memory stock.

(028) Change in Frac Tasks Comp in Previous Phase 0=

IF THEN ELSE(Months to Introduction Date=12,Input Fraction/TIME STEP,0)

Units: 1/Month

The Input Fraction is kept in this memory stock.

(029) Change in Frac Tasks Comp in Previous Phase 0 0=

IF THEN ELSE(Months to Introduction Date=12,Fraction of Advanced Task Completed this Model Year 0/TIME STEP,0)

Units: 1/Month

The Fraction of Advanced Tasks Completed at the end of the model year is kept in a memory stock.

(030) Curr Task Completion Rate = IF THEN ELSE(Months to Introduction Date=12,0,Actual Current Task Completion Rate)

Units: tasks/Month

Current Development Task Completion Rate is the actual current change rate. The flow is turned off at the instant at launch.

(031) Curr Task Completion Rate 0 = IF THEN ELSE(Months to Introduction Date=12,0,Actual Current Task Completion Rate 0)

Units: tasks/Month

Current Development Task Completion Rate is the actual current change rate. The flow is turned off at the instant at launch.

(032) Curr Task in Testing Launched = IF THEN ELSE(Months to Introduction Date=12,Current Tasks in Testing/TIME STEP,0)

Units: tasks/Month

Current Tasks Awaiting Testing that are Launched. On the launch date the stock of current tasks in testing is launched at once.

(033) Curr Task in Testing Launched 0 = IF THEN ELSE(Months to Introduction Date=12,Current Tasks in Testing 0/TIME STEP,0)

Units: tasks/Month

Current Tasks Awaiting Testing that are Launched. On the launch date the stock of current tasks in testing is launched at once.

(034) Curr Tasks Comp Launched = IF THEN ELSE(Months to Introduction Date=12,Current Tasks Completed/TIME STEP,0)

Units: tasks/Month

Current Completed Tasks that are Launched. The stock of completed tasks is emptied at the time of launch.

(035) Curr Tasks Comp Launched 0 = IF THEN ELSE(Months to Introduction Date=12,Current Tasks Completed 0/TIME STEP,0)

Units: tasks/Month

Current Completed Tasks that are Launched. The stock of completed tasks is emptied at the time of launch.

(036) Curr Tasks Failing Testing=

IF THEN ELSE(Months to Introduction Date=12,0,Fraction of Curr Tasks Defective*Curr Test ThroughPut)

Units: tasks/Month

Current Tasks Failing Testing is the fraction of current testing throughput which requires rework. The flow is turned off at the instant of launch.

(037) Curr Tasks Failing Testing 0=

IF THEN ELSE(Months to Introduction Date=12,0,Fraction of Curr Tasks Defective 0*Curr Test ThroughPut 0 )

Units: tasks/Month

Current Tasks Failing Testing is the fraction of current testing throughput which requires rework. The flow is turned off at the instant of launch.

(038) Curr Tasks in Rework Launched = IF THEN ELSE(Months to Introduction Date=12,Current Tasks to be Reworked/TIME STEP,0)

Units: tasks/Month

Current Tasks Requiring Rework that are Launched. At the time of launch, all the stock is emptied.

(039) Curr Tasks in Rework Launched 0 = IF THEN ELSE(Months to Introduction Date=12,Current Tasks to be Reworked 0/TIME STEP,0)

Units: tasks/Month

Current Tasks Requiring Rework that are Launched. At the time of launch, all the stock is emptied.

(040) Curr Tasks Not Comp Launched=

IF THEN ELSE(Months to Introduction Date=12,Current Tasks Not Completed/TIME STEP,0)

Units: tasks/Month

Current Tasks Not Completed launched. At the time of launch, the stock of current tasks not completed is launched at once.

(041) Curr Tasks Not Comp Launched 0=

IF THEN ELSE(Months to Introduction Date=12,Current Tasks Not Completed 0/TIME STEP,0)

Units: tasks/Month

Current Tasks Not Completed launched. At the time of launch, the stock of current tasks not completed is launched at once.

(042) Curr Tasks Passing Testing= IF THEN ELSE(Months to Introduction Date=12,0, (1-Fraction of Curr Tasks Defective)*Curr Test ThroughPut)

Units: tasks/Month

Current Tasks Passing Testing is the fraction of current testing throughput that doesn't require rework. The flow is turned off at the instant at launch.

(043) Curr Tasks Passing Testing 0= IF THEN ELSE(Months to Introduction Date=12,0, (1-Fraction of Curr Tasks Defective 0)*Curr Test ThroughPut 0)

Units: tasks/Month

Current Tasks Passing Testing is the fraction of current testing throughput that doesn't require rework. The flow is turned off at the instant at launch.

(044) Curr Tasks Reworked = IF THEN ELSE(Months to Introduction Date=12,0,Actual Current Task Rework Rate)

Units: tasks/Month

Current Task Rework Completion Rate is the actual current rework rate. The flow is turned off at the instant of launch.

(045) Curr Tasks Reworked 0 = IF THEN ELSE(Months to Introduction Date=12,0,Actual Current Task Rework Rate 0)

Units: tasks/Month

Current Task Rework Completion Rate is the actual current rework rate. The flow is turned off at the instant of launch.

(046) Curr Test ThroughPut = Current Tasks in Testing/Time to Test

Units: tasks/Month

Current Testing takes place with a constant delay of Time to Test.

(047) Curr Test ThroughPut 0=Current Tasks in Testing 0/Time to Test

Units: tasks/Month

Current Testing takes place with a constant delay of Time to Test.

(048) Current Advanced Ratio=

Units: dimensionless

The Current Advanced Ratio is the fraction of current tasks compared to advanced tasks.

(049) Current Tasks Awaiting Adv Work= INTEG (Incr in Curr Tasks Awaiting Adv Work-Incr in Curr Tasks, 0)

Units: tasks

The Current Tasks Awaiting Advanced Work are the tasks that await to be introduced into the Current Work Sector for the following model year. The product development process is a 2 year process so the advanced phase of the process takes place a year before the tasks are input as the current work.

(050) Current Tasks Awaiting Adv Work 0= INTEG (Incr in Curr Tasks Awaiting Adv Work 0-Incr in Curr Tasks 0,0)

Units: tasks

(051) Current Tasks Completed= INTEG (Curr Tasks Passing Testing-Curr Tasks Comp Launched, 0)

Units: tasks

Current Tasks Completed and Passed Testing. The stock accumulates with the passing of testing. When launch time comes all the stock is emptied.

(052) Current Tasks Completed 0= INTEG (Curr Tasks Passing Testing 0-Curr Tasks Comp Launched 0, 0)

Units: tasks

Current Tasks Completed and Passed Testing. The stock accumulates with the passing of testing. When launch time comes all the stock is emptied.

(053) Current Tasks in Testing= INTEG ( Curr Task Completion Rate+Curr Tasks Reworked-Curr Tasks Failing Testing-Curr Tasks Passing Testing- Curr Task in Testing Launched,0)

Units: tasks

Current Development Tasks Awaiting Testing. The inflows to this stock are the current task completion rate and current tasks rework rate. The outflows are the failing test rate, passing test rate and the pulse of outflow at launch. So, the stock accumulates with work being done and decreases with work being tested and it is reset for each new model year.

(054) Current Tasks in Testing 0= INTEG (Curr Task Completion Rate 0 +Curr Tasks Reworked 0-Curr Tasks Failing Testing 0-Curr Tasks Passing Testing 0- Curr Task in Testing Launched 0, 0)

Units: tasks

(055) Current Tasks Not Completed= INTEG (Incr in Curr Tasks-Curr Task Completion Rate-Curr Tasks Not Comp Launched, 0)

Units: tasks

Current Development Tasks Not Yet Completed. After work is done in the Advanced Sector, the corresponding current work is introduced into the Current Sector. The outflow of this stock is the current task completion rate. And at the time of launch all the stock is emptied to be launched.

(056) Current Tasks Not Completed 0= INTEG (Incr in Curr Tasks 0-Curr Task Completion Rate 0-Curr Tasks Not Comp Launched 0, 0)

Units: tasks

all the stock is emptied to be launched.

(057) Current Tasks to be Reworked= INTEG (+Curr Tasks Failing Testing-Curr Tasks Reworked-Curr Tasks in Rework Launched, 0)

Units: tasks

Current Tasks Awaiting Rework. The main inflow during the current development process is the tasks failing testing. The corresponding outflow is tasks reworked. When the cycle ends the remainder of the stock is launched.

(058) Current Tasks to be Reworked 0= INTEG (+Curr Tasks Failing Testing 0-Curr Tasks Reworked 0-Curr Tasks in Rework Launched 0, 0)

Units: tasks

(059) Decr in Frac Comp in Prior Prev Phase= IF THEN ELSE(Months to Introduction Date=12,Frac Comp in Prior Previous Phase/TIME STEP,0)

Units: 1/Month

The memory stock of the Fraction of Tasks Completed in Prior Previous Phase is reset at the end of the model year.

(060) Decr in Frac Comp in Prior Prev Phase 0= IF THEN ELSE(Months to Introduction Date=12,Frac Comp in Prior Previous Phase 0/TIME STEP,0)

Units: 1/Month

The memory stock of the Fraction of Tasks Completed in Prior Previous Phase is reset at the end of the model year.

(061) Decr in Frac Comp in Prior Prev Phase 0 0= IF THEN ELSE(Months to Introduction Date=12,Frac Comp in Prior Previous Phase 0 0/TIME STEP,0)

Units: 1/Month

The memory stock of the Fraction of Tasks Completed in Prior Previous Phase is reset at the end of the model year.

(062) decr in frac defective at Launch =

IF THEN ELSE(Frac Defective at Launch>0,Frac defective for Launched Model/TIME STEP,0)

Units: defects/(task*months)

The decrease in Fraction defective at Launch is the outflow to the memory stock which resets the previous cycle's information.

(063) Decr in Frac Tasks Comp in Prev Phase=

IF THEN ELSE(Months to Introduction Date=12,Fraction of Tasks Completed in Previous Phase/TIME STEP,0)

Units: 1/Month

The memory stock of the Fraction of Tasks Completed in Previous Phase is emptied at the end of the model year and then transferred into the next memory stock.

(064) Decr in Frac Tasks Comp in Prev Phase 0=

IF THEN ELSE(Months to Introduction Date=12,Fraction of Tasks Completed in Previous Phase 0/TIME STEP,0)

Units: 1/Month

The memory stock of the Fraction of Tasks Completed in Previous Phase is emptied at the end of the model year and then transferred into the next memory stock.

(065) Decr in Frac Tasks Comp in Prev Phase 0 0=

IF THEN ELSE(Months to Introduction Date=12,Fraction of Tasks Completed in Previous Phase 0 0/TIME STEP,0)

Units: 1/Month

The memory stock of the Fraction of Tasks Completed in Previous Phase is emptied at the end of the model year and then transferred into the next memory stock.

(066) Defects Per Task Failing Test=

Units: defects/task

The corresponding defects per each task failing test. The value 1 means that there is one defect per task that fails testing.

(067) Defects Per Task Passing Test=

Units: defects/task

The corresponding defects per each task passing test. The value 0 means that there is no defects per task that passes testing.

(068) Design Freeze=IF THEN ELSE(Months to Introduction Date<freeze date*(step(1,freeze policy start)-step(1,freeze policy end)),0,1)

Units: dimensionless

Switch to Freeze Designs. The switch is on when it returns value 0 and off when it returns value 1. This is so because the value of "Design Freeze" is multiplied to "actual current rework rate".

(069) Development Engineers = 300

Units: engineers

The number of Development Engineers available.

(070) Engineering Capacity = Total Engineer Hours/Hours Per Task

Units: tasks/Month

Engineering capacity is the number of tasks that can be completed each month when certain number of hours (Hours Per Task) are allocated to each task.

(071) excess adv cap=Cap To be Allocated to Adv Tasks-Actual Advanced Task Completion Rate

Units: tasks/Month

The Excess Advanced Capacity is the remaining capacity after all the work is done.

(072) excess adv cap 0=Cap To be Allocated to Adv Tasks 0-Actual Advanced Task Completion Rate 0

Units: tasks/Month

The Excess Advanced Capacity is the remaining capacity after all the work is done.

(073) FINAL TIME = 360

Units: months

The final time for the simulation.

(074) Frac Advanced Tasks Under Current Method=0.25+step(Additional Fraction of Methodology Introduced,Methodology Intro Date)

Units: dimensionless

The Fraction of Advanced Tasks Under Current Method is the total fraction of the methodology introduced into the simulation. It is computed by summing the base fraction, 0.25 and the step function of the additional methodology introduced.

(075) Frac Comp in Prior Previous Phase= INTEG (+Decr in Frac Tasks Comp in Prev Phase-Decr in Frac Comp in Prior Prev Phase,1)

Units: dimensionless

This is the memory stock of the Fraction of Advanced Tasks Completed in Prior Previous Phase.

(076) Frac Comp in Prior Previous Phase 0= INTEG (+Decr in Frac Tasks Comp in Prev Phase 0-Decr in Frac Comp in Prior Prev Phase 0,1)

Units: dimensionless

This is the memory stock of the Fraction of Advanced Tasks Completed in Prior Previous Phase.

(077) Frac Comp in Prior Previous Phase 0 0= INTEG (+Decr in Frac Tasks Comp in Prev Phase 0 0-Decr in Frac Comp in Prior Prev Phase 0 0,1)

Units: dimensionless

This is the memory stock of the Fraction of Advanced Tasks Completed in Prior Previous Phase.

(078) Frac Defective at Launch= ZIDZ(Curr Tasks in Rework Launched*Defects Per Task Failing Test+Curr Tasks Not Comp Launched*Defects Per Task Failing Test+Curr Tasks Comp Launched*Defects Per Task Passing Test+Curr Task in Testing Launched*Fraction of Curr Tasks Defective*Defects Per Task Failing Test,Curr Tasks Comp Launched+Curr Task in Testing Launched+Curr Tasks in Rework Launched+Curr Tasks Not Comp Launched)

Units: defects/task

Fraction of Tasks Introduced to the Market that are Defective. This is the sum of the defects introduced by the launch flows divided by the total launch flows. Here, the launch flows that contribute to the defects on the market are Current Tasks not Completed and Current Tasks in Rework. These are assumed to be fully defective. For Current Tasks in Testing, only the "Fraction of Current Tasks Defective" has defects. The launch flow from Current Tasks Completed is assumed to be defect-free.

(079) Frac defective for Launched Model = INTEG(+incr in frac defective at Launch-decr in frac defective at Launch,0)

Units: defects/task

The Fraction defective for Launched Model is the memory of the fraction of defects at the time of launch. This stock remembers the information until the next launch.

(080) Frac of Avoidable Defects=Total Defect Frac*Historical Comp Frac of Advanced Tasks

Units: dimensionless

The Maximum Fraction of Avoidable Defects is the defects that can be eliminated by doing the advanced work. It is a "fraction" of the Total Defect Fraction. This "fraction" is the Historical Completion Fraction of Advanced Tasks, determined by the size of the set of tools currently in use. Thus, if there were many advanced tasks completed historically, then the Maximum Fraction of Avoidable Defects is higher.

(081) Frac of Avoidable Defects 0=Total Defect Frac*Historical Comp Frac of Advanced Tasks 0

Units: dimensionless

(082) Frac of UnAvoidable Defects=(1-Historical Comp Frac of Advanced Tasks)*Total Defect Frac

Units: dimensionless

The Maximum Fraction of Avoidable Defects is a "fraction" of the Total Defect Fraction. This "fraction" is the Historical Completion Fraction of Advanced Tasks, determined by the size of the set of tools currently in use. Thus, if there were many advanced tasks completed historically, then the Maximum Fraction of UnAvoidable Defects is lower.

(083) Frac of UnAvoidable Defects 0=(1-Historical Comp Frac of Advanced Tasks 0)*Total Defect Frac

Units: dimensionless

(084) Fraction of Advanced Task Completed this Model Year=

ZIDZ(Advanced Tasks Completed,Advanced Tasks Completed+Advanced Tasks Not Completed)

Units: dimensionless

This is the Fraction of Advanced Tasks Completed this Model Year. This value shows the instantaneous fraction completed in time.

(085) Fraction of Advanced Task Completed this Model Year 0=

ZIDZ(Advanced Tasks Completed 0,Advanced Tasks Completed 0+Advanced Tasks Not Completed 0)

Units: dimensionless

This is the Fraction of Advanced Tasks Completed this Model Year. This value shows the instantaneous fraction completed in time.

(086) Fraction of Curr Tasks Defective=

Frac of Avoidable Defects*(1-Fraction of Tasks Completed in Previous Phase)+Frac of UnAvoidable Defects

Units: dimensionless

The Fraction of Current Tasks Defective is the sum of the UnAvoidable Defects and the Avoidable Defects. The contribution by the "Fraction of the Avoidable Defects" is determined by the Fraction of Tasks Completed in the Previous Phase. The more

tasks completed the less the defect fraction.

(087) Fraction of Curr Tasks Defective 0=

Frac of Avoidable Defects 0*(1-Fraction of Tasks Completed in Previous Phase 0)+Frac of UnAvoidable Defects 0

Units: dimensionless

(088) Fraction of Tasks Completed in Previous Phase= INTEG (+Change in Frac Tasks Comp in Previous Phase-Decr in Frac Tasks Comp in Prev Phase,1)

Units: dimensionless

This is the memory stock of the Fraction of Tasks Completed in Previous Phase.

(089) Fraction of Tasks Completed in Previous Phase 0= INTEG (+Change in Frac Tasks Comp in Previous Phase 0-Decr in Frac Tasks Comp in Prev Phase 0,1)

Units: dimensionless

This is the memory stock of the Fraction of Tasks Completed in Previous Phase.

(090) Fraction of Tasks Completed in Previous Phase 0 0= INTEG ( +Change in Frac Tasks Comp in Previous Phase 0 0-Decr in Frac Tasks Comp in Prev Phase 0 0,1)

Units: dimensionless

This is the memory stock of the Fraction of Tasks Completed in Previous Phase.

(091) freeze date=

Units: months

Date at Which Designs are Frozen in each 12 month cycle. The value represents the date in "months to job one". For example, a value of 6 would mean that design is frozen when there are less than 6 months to job one.

(092) freeze policy end = 1e+009

Units: Month

Date when freeze policy ends during the simulated time.

(093) freeze policy start=

Units: Month

Date at Which Freeze Policy Starts during the simulation time.

(094) Historical Comp Frac of Advanced Tasks=

Adv Task Comp Last Yr 2/Total Number of Possible Adv Tasks

Units: dimensionless

The Historical Completion Fraction of Advanced Tasks is calculated by the Average Advanced Tasks Completed divided by the Total Number of Possible Advanced Tasks. This represents the efficacy of the tool set currently in use. This captures the organization's current ability to use the tools it has at its disposal. It is calculated as a moving average of the organization's current knowledge of the tools. Once a tool is learned, time is required to develop experience before it can be used effectively. The average time required to gain such experience is assumed to be two model years.

(095) Historical Comp Frac of Advanced Tasks 0=

Adv Task Comp Last Yr 2 0/Total Number of Possible Adv Tasks

Units: dimensionless

(096) Hours Per Engineer = 200

Units: hours/engineer/Month

The average number of hours an engineer works in a month.

(097) Hours Per Task = 200

Units: hours/task

The average number of hours it takes to complete a task.

(098) Inc in Adv Comp Last Yr 1= IF THEN ELSE(Months to Introduction Date=12,Adv Task Comp Last Yr 1*((Learning Delay Per Stage-1)/Learning Delay Per Stage)/TIME STEP+Advanced Completed Flushed*(1/Learning Delay Per Stage),0)

Units: tasks/Month

This is the inflow to the delay representing Learning of the new tool set.

(099) Inc in Adv Comp Last Yr 1 0= IF THEN ELSE(Months to Introduction Date=12,Adv Task Comp Last Yr 1 0*((Learning Delay Per Stage-1)/Learning Delay Per Stage)/TIME STEP+Advanced Completed Flushed 0*(1/Learning Delay Per Stage),0)

Units: tasks/Month

This is the inflow to the delay representing Learning of the new tool set.

(100) Inc in Adv Comp Last Yr 2= IF THEN ELSE(Months to Introduction Date=12,Adv Task Comp Last Yr 2*((Learning Delay Per Stage-1)/Learning Delay Per Stage)/TIME STEP +Adv Task Comp Last Yr 1*(1/Learning Delay Per Stage)/TIME STEP,0)

Units: tasks/Month

This is the inflow to the delay representing Experience with the new tool set.

(101) Inc in Adv Comp Last Yr 2 0= IF THEN ELSE(Months to Introduction Date=12,Adv Task Comp Last Yr 2 0*((Learning Delay Per Stage-1)/Learning Delay Per Stage)/TIME STEP +Adv Task Comp Last Yr 1 0*(1/Learning Delay Per Stage)/TIME STEP,0)

Units: tasks/Month

This is the inflow to the delay representing Experience with the new tool set.

(102) Incr In Adv Com Two Yrs prior 1=

IF THEN ELSE(Months to Introduction Date=12,Adv Task Comp Last Yr 1/TIME STEP,0)

Units: tasks/Month

This is the outflow to the delay representing Learning of the new tool set.

(103) Incr In Adv Com Two Yrs prior 1 0=

IF THEN ELSE(Months to Introduction Date=12,Adv Task Comp Last Yr 1 0/TIME STEP,0)

Units: tasks/Month

This is the outflow to the delay representing Learning of the new tool set.

(104) Incr In Adv Com Two Yrs prior 2=

IF THEN ELSE(Months to Introduction Date=12,Adv Task Comp Last Yr 2/TIME STEP,0)

Units: tasks/Month

This is the outflow to the delay representing Experience with the new tool set.

(105) Incr In Adv Com Two Yrs prior 2 0=

IF THEN ELSE(Months to Introduction Date=12,Adv Task Comp Last Yr 2 0/TIME STEP,0)

Units: tasks/Month

This is the outflow to the delay representing Experience with the new tool set.

(106) Incr in Curr Tasks=

IF THEN ELSE(Months to Introduction Date=12,Current Tasks Awaiting Adv Work/TIME STEP,0)

Units: tasks/Month

The Increase in Current Tasks is the introduction of the current work at the beginning of the model year.

(107) Incr in Curr Tasks 0=

IF THEN ELSE(Months to Introduction Date=12,Current Tasks Awaiting Adv Work 0/TIME STEP,0)

Units: tasks/Month

The Increase in Current Tasks is the introduction of the current work at the beginning of the model year.

(108) Incr in Curr Tasks Awaiting Adv Work=

IF THEN ELSE(Months to Introduction Date=12,New Changes per Yr/TIME STEP,0)

Units: tasks/Month

The Increase in Current Tasks Awaiting Advanced Work is the flow of the corresponding current work that is introduced into the advanced work sector. The product development process is a 2 year process so the advanced phase of the process takes place a year before the actual project becomes the current work.

(109) Incr in Curr Tasks Awaiting Adv Work 0=

IF THEN ELSE(Months to Introduction Date=12,New Changes per Yr/TIME STEP,0)

Units: tasks/Month

(110) incr in frac defective at Launch=

IF THEN ELSE(Frac Defective at Launch>0,Frac Defective at Launch/TIME STEP,0)

Units: defects/task/months

The Increase in Fraction defective at launch is input into the memory stock.

(111) ind adv comp rate=

Advanced Tasks Not Completed/min time to do task

Units: tasks/Month

Indicated Completion Rate of Advanced Tasks. This represents the maximum work rate for advanced new work. It is the rate at which work can be done when capacity is not a constraint and the least amount of time is invested.

(112) ind adv comp rate 0=

Advanced Tasks Not Completed 0/min time to do task

Units: tasks/Month

(113) ind curr comp rate=

Current Tasks Not Completed/min time to do task

Units: tasks/Month

Indicated Completion Rate of Current Engineering Changes. This represents the maximum work rate for current new work. It is the rate at which work can be done when capacity is not a constraint and the least amount of time is invested.

(114) ind curr comp rate 0=

Current Tasks Not Completed 0/min time to do task

Units: tasks/Month

(115) ind curr rework rate=

Current Tasks to be Reworked/min time to do task

Units: tasks/Month

Indicated Completion Rate for Current Rework. This represents the maximum work rate for current rework. It is the rate at which work can be done when capacity is not a constraint and the least amount of time is invested.

(116) ind curr rework rate 0=

Current Tasks to be Reworked 0/min time to do task

Units: tasks/Month

(117) INITIAL TIME = 0

Units: months

The initial time for the simulation.

(118) Input Fraction=

Time/FINAL TIME

Units: dimensionless

(119) Learning Delay in Years=

1e+009

Units: months

This represents the delays for Learning and gaining Experience in the new tool set. The variable's actual units are in years but due to technical reasons the units here are set to months. So, "Learning Delay in Years = 1" means that Learning Delay is 1 year.

(120) Learning Delay Per Stage=

Learning Delay in Years/2

Units: months

This represents the delays for Learning and gaining Experience in the new tool set.

(121) Length of Model Year = 12

Units: months

The length of each model year is shown in units of "months".

(122) Methodology Intro Date=

1e+009

Units: Month

Date at which Development Methodology is introduced to the Organization during the simulation.

(123) min time to do task=

Units: Month

The Minimum time to do task is given to be 1 month. This value is used to determine the flow of the maximum work rates.

(124) Months to Introduction Date=

MAx(Length of Model Year-MODULO(Time,Length of Model Year),0)

Units: months

Months Until Current Projects are Launched. The count-down of each model year.

(125) New Advanced Tasks Per Yr=

New Changes per Yr/Current Advanced Ratio*Frac Advanced Tasks Under Current Method

Units: tasks

The New Advanced Tasks introduced Per Year is the fraction of the New Changes to be introduced in the Current Work according to the Current Advanced Ratio, and is also dependent on the introduction of Methodology.

(126) New Advanced Tasks Per Yr 0=

New Changes per Yr/Current Advanced Ratio*Frac Advanced Tasks Under Current Method

Units: tasks

(127) New Changes per Yr=Base Chng Rate+step(Step Input,Step Date)+Pulse Input*pulse(Pulse Date,Pulse Width)

Units: tasks

The Number of New Development Tasks Introduced per Year. The changes are the sum of the Base Change Rate, a step input and a pulse input.

(128) Pulse Date=

192

Units: Month

The Pulse Date is the instant in time the pulse function starts inputting the Pulse Input.

(129) Pulse Input = 0

Units: tasks

The Pulse Input is the additional amount of new tasks introduced into the product development process.

(130) Pulse Width = 1

Units: Month

The Pulse Width is the time duration of the pulse function. For example, with a pulse width of 1 (month) the additional amount of new tasks introduced by the pulse function will be the Pulse Input spread over the 1 month.

(131) SAVEPER =

TIME STEP

Units: months

The frequency with which output is stored.

(132) Step Date = 192

Units: Month

The Step Date is the instant in time the step function starts inputting the Step Input.

(133) Step Input=

Units: tasks

The Step Input is the additional amount of new tasks introduced by the step function.

(134) TIME STEP = 0.25

Units: months

The time step for the simulation.

(135) Time to Test = 1

Units: months

It is assumed Testing would take, on average, one month.

(136) Total Advanced Tasks Flushed=

Advanced Completed Flushed+Advanced Not Completed Flushed

Units: tasks/Month

At the end of each model year cycle, the total of the advanced tasks that are flushed are calculated.

(137) Total Advanced Tasks Flushed 0=

Advanced Completed Flushed 0+Advanced Not Completed Flushed 0

Units: tasks/Month

At the end of each model year cycle, the total of the advanced tasks that are flushed are calculated.

(138) Total Current Work to Be Completed = Current Tasks Not Completed+Current Tasks to be Reworked

Units: tasks

The Total Current Work to be Completed is the sum of the new tasks and the tasks needing rework.

(139) Total Current Work to Be Completed 0 = Current Tasks Not Completed 0+Current Tasks to be Reworked 0

Units: tasks

The Total Current Work to be Completed is the sum of the new tasks and the tasks needing rework.

(140) Total Defect Frac=

0.75

Units: dimensionless

This is the Total Defect Fraction.

(141) Total Engineer Hours = Development Engineers*Hours Per Engineer

Units: hours/Month

Total Engineering Hours available each month.

(142) Total Number of Possible Adv Tasks=

Base Chng Rate/Current Advanced Ratio

Units: tasks

The Total Number of Possible Advanced Tasks is half that of the Base Change Rate, here Current Advanced Ratio is 2. This represents the number of tasks that should be completed to achieve the maximum benefit of the toolset used.