Question

An automobile final assembly plant is being planned for an annual production of 150,000 cars. The plant will operate one shift, 250 days per year, but the duration of the shift (hr/shift) is to be determined. The plant will be divided into three departments: (1) body shop, (2) paint shop, and (c) general assembly. The body shop welds the car bodies, and the paint shop coats the welded car bodies. Both of these departments are highly automated. The general assembly department has no automation, but a moving conveyor is used to transport the cars through the manual workstations. A total of 14.0 hours of direct labor (work content time) are accomplished in general assembly. Based on previous lines installed by the company, it is anticipated that the following design parameters will apply to the general assembly department:line efficiency = 95%, balance efficiency = 94%, repositioning time = 0.10 min, and manning level = 2.5. If the plant must produce 60 cars per hour, determine the following for the general assembly department: (a) The number of hours the shift must operate.(b) The number of workers required.(c) The number of workstations.

Answer 1

Answer:

a. Rp= 10.0hr

b. Tc= 1052 workers

c. n= 421 workstations

Explanation:

(a) Rp= Da/250Hsh. Rearranging, Hsh= Da/250Rp= 150,000/250(60) = 10.0 hr

(b) Tc= 60E/Rp= 60(0.95)/60 = 0.95 minTs= Tc– Tr= 0.95 – 0.10 = 0.85 minw= Min Int 14.0(60)/0.85(0.94) = 1051.3 rounded up to 1052 workers

(c) n= w/M= 1052/2.5 = 421 workstations