CIVE 605 - Decision Support Systems in Construction
Winter 2022
Assignment 1
1) A company manufactures three types of chemicals: A, B, and C. These chemicals are produced via
two production processes. Running process 1 for an hour cost $6, and yields 4 units of A, 1 of B, and
2 of C. Running process 2 for an hour cost $3 and produces 1 unit of A and 1 of B. To meet the
demand, at least 30 units of A, 10 of B, and 14 of C must be produced daily.
a. Graphically determine a daily production plan that minimizes the cost.
b. Develop Excel model and solve it using “Solver”.
2) A 50,000 sft painting job is under tight schedule. There is only 1 crew available. However, you (as the
project manager) have the option of increasing the daily working hours. The normal work hour is 8
hours/day, but it can be increased up to 12 hours/day (half hour incremental). The normal
productivity is 210 sft/hour which goes down by 3.5% for every half hour increment of overtime hours.
The normal labour cost is 450 $/day, but 2.5% overtime has to be paid for every half hour increment.
a. Develop an Excel spreadsheet model for the given scenario and examine the sensitivity of project
duration (days) to the "daily working hour" options. Show your results graphically.
b. Determine the minimum project duration in days.
c. The project setup cost is $6,000, recurring indirect cost is $200/day, and material cost is
0.40$/sft. Determine the minimum project cost, and its corresponding "daily working hour" option.
d. Use “Solver” to determine the "daily working hour" option for the minimum project cost.
e. Which "daily work hour" option would you choose for your project and why? Discuss your
findings.
Notes:
• This is an individual assignment, and you are expected to work on your own.
• Total marks: 20
• Due date: Tuesday February 8th, 2022, by 1:00 PM.
• Deliverables: A short report (in word document), and the Excel file.
• Please submit your report on eClass through designated link.