The manager of a computer help center needs to determine a shift schedule for
his sta . The center is open from 8am until midnight (12am), and is divided into four shifts. The number of employees needed on each shift is as follows: 4 on the rst shift (8am-12pm), 10 on the second shift (12pm-4pm), 8 on the third shift (4pm-8pm), and 6 on the last shift (8pm-12am). Two types of employees can be hired to sta the computer center: full-time employees and part-time employees. Full-time employees must be hired for two consecutive shifts, and can be hired to start in the rst, second or third shift. Part-time employees are hired for a single shift. Full-time employees are paid $14 an hour, while part-time employees are paid $12 an hour. Lastly, during each of the shifts, there must be at least two full-time employees sta ed for every part-time employee.
Formulate a linear programming model to satisfy the stang requirements at minimum cost.

Respuesta :

Explanation:

we have to define certain variables in ordet for us to formulate the linear programming model

[tex]aj =[/tex] the number of full time staff hired at time j

[tex]bj=[/tex] number of full time staff hired at time j

1 full time emploer 8hrs x 14$

= 112 dollars

1 part time worker = 4hrs x $12

= 48 dollars

we set up the model as:

[tex]minimize 112(a_{1} +a_{2} +a_{3} )+48(b_{1} +b_{2} +b_{3})[/tex]

[tex]a_{1} + b_{1} = 4[/tex]

[tex]a_{1} +a_{2} +b_{2} = 10[/tex]

[tex]a_{2} +a_{3} +b_{3} =8[/tex]

[tex]a_{3} +b_{4} =6[/tex]

[tex]a_{1} >2b_{1}[/tex]

[tex]a_{1} +a_{2} \geq 2b_{2}[/tex]

[tex]a_{2} +a_{3} \geq 2b_{3}[/tex]

[tex]a_{3} \geq 2b_{4}[/tex]

[tex]a_{j} ,b_{j} \geq 0[/tex]

∀j