Week 3 Assignment

Response to Changing Delay Times Until now all our tests have considered the response of different delays to changing inputs. We have assumed the delay time has remained constant. Now we consider what happens when the delay time changes. The delay times for both material and information delays can change. For example, raising the speed limit on the interstate highways from 55 to 65 reduced the delay in the transport of raw materials from supplier to customer (assuming any truckers were actually obeying the 55-mph speed limit in the first place). Similarly, replacing a paper-based invoicing system with a globally integrated, real-time client-server network can reduce the delay in the perception by senior management of the order rate for their firms products.

Do the Challenge "Response of Delays to Changing Delay Times"

• For part 1 and part 2 of the challenge, do not use the computer. Be sure to sketch the behavior you expect for each case before you build and simulate the models.

• Hand in the graphs showing your estimate of the behavior for each case. Your grade does not depend on the accuracy of your answer to this question. Explain your graphs briefly.
• For part 3 of the challenge you will simulate the effect of the changes in delay times described in parts 1 and 2. To do so you need to modify the equation for the delay time in your models so that it can change.

To implement the test, modify the equation for the delay time to:

• Delay Time = IF_THEN_ELSE(Time < Time to Change Delay Time, Base Delay Time, New Delay Time)

• Where the Time to Change Delay Time is the time at which the value of the delay time will switch from the Base Delay Time to the New Delay Time. The challenge does not require you to experiment with changing delay times for the pipeline delay.
• Hand in plots of the behavior of the first- and third-order material delay when the delay time changes from 5 to 10 days, and from 5 to 2.5 days (all changes occur on day 5). Was your intuition correct? Explain the dynamics and the equilibrium state (the magnitude of the stock in transit). If there are differences between the response of the material and information delays, explain why.

Hand in the diagrams and documented equation listings for your models (including the first order, third order, and pipeline material delays, and for the information smoothing delay).