Premier Consulting has two consultants, Avery and Baker, who can be scheduled to work for clients up to a maximum of 160 hours each over the next four weeks. A third consultant, Campbell, has some administrative assignments already planned and is available for clients up to a maximum of 140 hours over the next four weeks. The company has four clients with projects in process. The estimated hourly requirements for each of the clients over the four-week period are
Client
Hours
A
180
B
75
C
100
D
85
Hourly rates vary for the consultant-client combinations and are based on several factors, including project type and consultant’s experience. The rates (dollar per hour) for each consultant-client combination are
Consultant
Client A
Client B
Client C
Client D
Avery
100
125
115
100
Baker
120
135
115
120
Campbell
155
150
140
130
Formulate the problem as a linear program, with the optimal solution providing the hours each consultant should be scheduled to work for each client in order to maximize the consulting firm’s billings. What is the schedule and what is the total billing?
New information shows that Avery doesn’t have the experience to be scheduled for Client B. If this assignment is not permitted, what impact does it have on total billings? What is the revised schedule?
Problem II
In a job shop operation, four jobs may be performed on any of four machines. The number of hours required for each job on each machine is summarized in the table. Formulate a linear program to minimize the total time job-machine assignment.
Machine
Job
A
B
C
D
1
22
18
32
26
2
22
24
12
16
3
24
30
26
24
4
26
30
28
20
Problem III
Adirondack Paper Mills, Inc., has paper plants in Augusta, Maine and Tupper Lake, New York. Warehouse facilities are located in Albany, New York and Portsmouht, New Hampshire. Distributors are located in Boston, New York and Philadelphia. The plant capacities and distributor demands for next month are as follows:
Plant
Capacity (units)
Distributor
Demand (units)
Augusta
300
Boston
150
Tupper Lake
100
New York
100
Philadelphia
150
The unit transportation costs ($) for shipments from the two plants to the two warehouses and from the two warehouses to the three distribution centers are as follows:
Warehouse
Plant
Albany
Portsmouth
Augusta
7
5
Tupper Lake
3
4
Distributor
Warehouse
Boston
New York
Philadelphia
Albany
8
5
7
Portsmouth
5
6
10
Formulate the Adirondack Paper Mills problem as a linear programming problem. What is the minimum-cost shipping schedule?