learning curve simulation in Enterprise Dynamics

[NinaK]

Is it possible to consider learning curve in simulation of employees efficiency in tasks ? (time of performing a task is decreasing till certain limit depending on number of a task repetition)

Is it possible to write 4D script of a cycle time that it will decrease depending on number of times task is performed?

What software is better for such simulations : Enterprise Dynamics or Arena?

[NinaK]

maybe, someone knows how to change efficiency depending on number of times tasks in performed??

[NinaK]

maybe, someone knows how to change efficiency depending on number of times tasks in performed (in Arena)??

still i cannot decide what software is better for modelling the workflow arena or ED?

does anyone have experience in simulation of tasks allocation? please, help

[elammers]

Hi Nina,

In ED, one way to model variation of cycletime depending on #tasks performed is as follows:

1. Define a global variable (called "v_Efficiency", for example)
2. Each time a part enters the server, check to see if this variable should be updated. This decision would depend on your threshold for # tasks in which the efficiency is improved. An example of this is:

IF( INPUT(C) < 100, {If the operator has processed less than 100 parts}
v_EFFICIENCY := 0.80,
IF( INPUT(C) >= 100, {If the operator has processed 100 parts or more}
v_EFFICIENCY := 0.95,
IF( INPUT(C) >= 200, {If the operator has processed 200 parts or more}
v_EFFICIENCY := 1.00
)
)
)

3. In the cycletime field of that server, assuming the fastest time is 30 seconds, you would type in:

30/v_EFFICIENCY


I would assume a similar approach will also work in Arena.

Good luck!
Eric

[ewilliams]

E. Lammers's response is excellent and generalizable. In the software being used, find the system variable keeping track of the number of times the task has been done (most softwares provide such a system variable) and use it to define the task time as a decreasing function of the number of times the task has been done (this time can be assigned to a modeler-defined variable used as the cycle time (task time). Furthermore, if the time required increases with the number of task completions (modeling fatigue of a human operator, for example), the function can be an increasing (versus a decreasing) function.

[NinaK]

thank you for your help.

I ended up to model my system of tasks allocation in Arena.
The learning curve can also be modelled here rather easy , the last thing that I cannot do there is to identify what resource performs what task and to model their efficiency accoring to it.

for example, I have 3 types of tasks. they are performed by 3 types of employees; employees are grouped in sets. Efficiency of different employees grows differently depending on a task performed. I cannot make system "to remember" what task what performed by what employee and connect it with their efficiency. What I did ,it's just approximate growth of their efficiency as a group.

hm, i read again my post. perhaps, it's rather difficult to understand what i am asking... It's more easier to understand looking at the model. so if someone is interested, I can just send it

[kvasudevan]

Nina,

Guess this response is overdue!

If you still have the open issue that you described, send me the model - we can take a look at it.

Karthik, PMC