Heckman of Saul and Saul Consultants has get a request from Deborah, the head of Human Resources, to make an interactive icon-and-menu-driven software package to be used by the advantages specialists in her department.  Based on preliminary discussions with Deborah, Heckman has identified two basically different types of functions that the package will have to serve, so he is planning on having it written in two modules.  Based on this initial information, Heckman has broken the project down into 8 basic activities along with their predecessors and estimated times as follows:

ACTIVITY    DESCRIPTION        PREDECESSOR    TIME (in weeks)
A        Survey users' needs            --                           2
B        Design graphic icons            A                           3
C        Develop flowchart            A                               1
D        Design input/output screens        B, C                 3

E        Code module 1            C                                    4

F        Code module 2            C                                    5
G        Merge modules and graphics        D, E, F             1
H        Test program                G                                   2
    
(a)    Illustrate a project network for the above activities.
(b)    Verify which activities are critical
(c)    Verify which activities are non-critical and their respective slack times.
(d)    How long will the project take to accomplish?