General Foundry, Inc., a metal works plant in Milwaukee, has long been trying to avoid the expense of installing air pollution control equipment. The local environment protection group has recently given the foundry 16 weeks to install a complex air filter system on its main smokestack. General Foundry has been warned that it may be forced to close unless the device installed in the allotted period. Lester Harky, the managing partner, wants to make sure that installation of the filtering system progressed smoothly and on time. General Foundry has identified the following eight activities that need to be performed and their sequential relationship.

Activity Description Time(Weeks) Immediate Predecessors
A Build internal components 4
B Modi roof and floor 2
C Construct collection stack 2 A
D Pour concrete and install frame 6 A, B
E Build high temperature burner 4 C
F Install pollution control system 3 C
G Install air pollution device 5 D, E
H Inspect and test 2 F, G

Required:
a. Construct the appropriate network diagram.
b. Which jobs can be delayed without delaying the project completion time?
c. Can General Foundry complete the project on time? Why or why not?