Page 49 - DCOM303_DMGT504_OPERATION_RESEARCH

Operations Research

Notes
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Case Study Ace Air Lines

he director of passenger services of Ace Air Lines was trying to decide how many
new stewardesses to hire and train over the next six months. He had before him the
Trequirements in number of stewardess flight hours needed.
Month Hours needed
Jan 8,000
Feb 7,000
March 8,000
April 10,000
May 9,000
June 12,000
It took one month to train a stewardess before she was able to be used on regular flights.
Hence, hiring had to be done a month before the need arose. Secondly, training of new
stewardess required the time of already trained stewardess. It took approximately 100
hours of regular stewardess time for each trainee during the month of training period. In
other words, the number of hours available for flight services by regular stewardesses
was cut by 100 hours for each trainee.
The director of passenger services was not worried about January since he had 60
stewardesses available. Company rules required that a stewardess could not work more
than 150 hours in any month. This meant that he had a maximum of 9,000 hours available
for January, one thousand in excess of his need (stewardesses were not laid off in such
cases merely worked fewer hours).
Company record showed that 10% of the stewardesses quit their jobs each month to be
married or for other reasons.
The cost of Ace Air lines for a regular stewardesses was ` 800 per month for salary and
fringe benefits, regardless of how many hours she worked. (She, of course, could not work
more than 150 hours.) The cost of a trainee was ` 400 per month for salary and fringe
benefits.
Question:
Formulate the above as a linear programming design to solve the problem of directory of
passenger services at minimum cost. Be sure to identify all the symbols that you use and
explain (briefly) all equations.

2.9 Summary

 Linear programming determines the way to achieve the best outcome (such as maximum
profit or lowest cost) in a given mathematical model and some list of requirements
represented as linear equations.

 It is a technique to ensure the optimum allocation of scarce resources in order to deliver
for the fulfillment of ever increasing demands in the market.

 Linear Programming is used as a helping tool in nearly all functional areas of management.
 The graphical method to solve linear programming problem helps to visualize the
procedure explicitly.

 It also helps to understand the different terminologies associated with the solution of LPP.

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