In the spring of 2020, one of Seaburg's cli­ents, a chlorine complex in nearby McIn­tosh, Alabama, was operating at 1OO percent of capacity-"sold-out." A maintenance turnaround was scheduled, however, to per­form major repairs to the facility. Turn­around activities, expected times for their completion, and sequencing constraints were as shown in Table 1 (below)

It should be noted from the above se­quencing constraints that job C (removal of the existing chlorine compressor and instal­lation of a new unit) constrained job N (changing the heat exchanger on the first ­effect evaporator) because a large crane was needed for both jobs. Plans called for the crane to perform the compressor job (C) before moving to the heat exchanger job (N). Seaburg’s staff advised the production manager that a second crane could be rented so that both jobs could be performed simultaneously. The rental of the crane would cost a base fee of $10,000 plus $8,000 per day. Contribution to profit and overhead from the production complex was estimated at $40,000 per day.

Activity	Predecessors	Normal Time(hours)	Normal time (days)	Crash Time (hours)	crash time (days)	Crash Cost
A	None	8	1	0	0
B	None	16	2	8	1	$15,000
C	A	72	9	48	6	$50,000
D	A	16	2	0	0
E	A	24	3	16	2	$10,000
F	A	36	4.5	24	3	$15,000
G	A	10	1.25	0	0
H	A	16	2	0	0
I	B	24	3	0	0
J	B	24	3	0	0
K	B	16	2	8	1	$15,000
L	B	8	1	0	0
M	CDEFGH	24	3	16	2	$35,000
N	BC	48	6	0	0
O	IJKLM	8	1	0	0
P	MNO	8	1	0	0

1. Should the second crane be rented? What is the minimal cost or maximum profit resulting from using the second crane? Assume in the analysis that “8” hours is equivalent to “one” days operation.   Also assume that Seaburg construction owns a crane and that their are no cost associated with it’s operation for this case. Therefore, only the cost of the second crane is applicable for your analysis. Use crashing.

Answer rating: 100% (QA)

Activity ES LS EF LF Slack A 0 0 8 8 0 B 0 64 16 80 64 C 8 8 80 80 0 D 8 80 24 96 72 E 8 72 32 96 64 ... View the full answer