Posted: November 13th, 2015

You have been retained as an external consultant to evaluate the collection operation of the city of Seremban. The basic questions center around the amount of time spent on off-route activities by the collectors. The collectors say that they spend less than 15 percent of each 8-h workday on off-route activities; management claims that the amount of time spent is more than 15 percent. You are given the following information that has been verified by both the collectors and management:

A hauled container system, without container exchange, is used.

ii. The average time spent driving from yard to the first container is 20 min, and no off-route

activities occur.

iii. The average pickup time per container is 5 min.

iv. The average time to drive between containers is 5 min.

v. The average time required to empty the container at disposal site is 5 min.

vi. The average round-trip distance to the disposal site is 10 mi/trip, and the haul

equation (a+bx) constant are a = 0.004 h/trip and b = 0.02 h/mi.

vii. The time required to redeposit a container after it has been emptied is 5min.

viii.The average time spent driving from the last container to the corporation yard is 15 min, and no off-route activities occur.

ix.The number of containers emptied per day is 10.

From this information, decide whether the truth is on the side of the collectors or the management. Is that possible for the management to increase 1 more collection trip?

Given :

Pick up time per trip ; Phcs = pc + uc+ dbc

Time per trip, Thcs         = (Phcs + s + a + bx)

Number of trips that can be made per day; Nd = [H (1-W) – (t1+t2)]/ Thcs