1. MATH143 Lec 7 Quantitative Methods
Charles W Jackson
Andrew Nunekpeku
MATH143 – Fall 2011 – Monday Week 3
11/25/2017

2. Agenda for today Excel Solver approach to LP problems
T2, Question 35 page 124 Ragsdale, solved in class
Translation to LP math
Organizing our numbers in Excel
Using Solver Plug-in
Identifying Objective Function
Identifying Decision Variables
Identifying Constraints
Setting up Options
Discovering the Optimum Program
Reminder A3 due tomorrow
MATH143 – Fall 2011 – Monday Week 3
11/25/2017

3. Word Problem Translation
Step One: What are the Decision Variables?
These are the minimum info required to describe what you want done during the period. What are the competing activities?
Step Two: What are the Constraints?
Which linear combinations of activities is limited? May be more or less than number of decision variables. Beware of implied non-negativity constraints.
MATH143 – Fall 2011 – Monday Week 3
11/25/2017

4. Word Problem Translation
Step Three: What is the Objective Function? Describe mathematically how you will decide which of two plans (levels of the activities) you would prefer. Often, this can be cast in the notion of maximizing profit for profit-making enterprises, but other situations might not be based on that metric.
MATH143 – Fall 2011 – Monday Week 3
11/25/2017

5. Word Problem
Valu-Com Electronics manufactures five different models of telecommunications interface cards for personal and laptop computers. As summarized in
the following table each of these devices requires differing amounts of printed circuit (PC) boards, resistors, memory chips, and assembly
MATH143 – Fall 2011 – Monday Week 3
11/25/2017

6. Per Unit Revenues and Costs
Word Problem, Continued
The unit wholesale price and manufacturing cost for each model are as follows:
Per Unit Revenues and Costs
Model
Hyperlink
Fastlink
Speedlink
Micolink
Etherlink
Wholesale Price
189
149
129
169
139
Mfg Cost
136
101 96
137
MATH143 – Fall 2011 – Monday Week 3
11/25/2017

7. Word Problem, Continued
In the next production period, Valu-Com has 80,000 sq. inches of PC board, 100,000 resistors, 30,000 memory chips, and 5,000 hours of assembly labour available. The company can sell all the product it can manufacture, but the marketing department wants to be sure that it produces at least 500 units of each product and at least twice as many fastlink cards as hyperlink cards while maximizing profit.
MATH143 – Fall 2011 – Monday Week 3
11/25/2017

8. Word Problem, Continued
Formulate LP problem
Create spreadsheet model
Establish solution
Could Value-Com make more money if it schedules its assembly workers to work overtime?
MATH143 – Fall 2011 – Monday Week 3
11/25/2017