Reference no: EM132176518
Activity Cycle Diagrams
PROBLEM #1: Model the following problem in EZStrobe. What is the duration of the operation with 5 trucks? What is the duration of the operation with 2 trucks? Please submit your Visio file and the answers to these questions.
PROBLEM #2: You are an earthwork subcontractor designing an operation to excavate 500,000 m3 of clay and haul it to a dump site 1600 meters away from the cut. You have already decided to use a CAT 375 excavator with a 2.75 m3 bucket and are deciding on the number of CAT D30D articulated trucks that you will use. Each D30D has a capacity of 16.5 m3.
The performance of a D30D on this operation is summarized as follows: Haul time: Uniform[5,6.75] minutes.
Dump time: Uniform[10,20] seconds, only one at a time. Return time: Uniform[1.7, 3] minutes.
Maneuver time at load area (to position under shovel): Uniform[0.1,0.3].
The performance of a CAT 375 on this operation is summarized as follows: Time to excavate: Uniform[0.1,0.25] minutes.
Time to swing loaded: Uniform[0.1,0.14] minutes.
Time to dump bucket unto truck: Uniform[0.04,0.10] minutes. Time to swing empty: Uniform[0.09, 0.13] minutes.
The excavator works on a cycle that includes the actual digging time, a 75 degree swing with the bucket loaded, the dumping of the material in the bucket unto a truck that has positioned in the right place (the excavator may need to wait for a truck to be there before dumping), and a 75 degree swing with the empty bucket.
The following cost data is available:
CAT 375: $4,750 transportation cost + $80/hr of use CAT D30D: $1,300 transportation cost + $44/hr of use Indirect costs of job: $125/hr
Prepare a simulation model and experiment with it to determine the number of trucks that will result in the least possible $/m3 for this job.
Show your $/m3 calculations in a spreadsheet for the options that you tried before determining the optimum number of trucks. Submit your Visio file and spreadsheet file. For this assignment, assume continuous 24 hour operation and disregard the effect of lunch and coffee breaks, fueling, and machine breakups.