Question

You work for Microsoft in their global cell phone group. You have been made project manager for the design of a new cell phone. Your supervisors have already scoped the project so you have a list showing the work breakdown structure and this includes major project activities. You must plan the project schedule and calculate project duration. Your boss wants the schedule on his desk tomorrow morning!
     You have been given the information in Exhibit 5.13. It includes all the activities required in the project and the duration of each activity. Also, dependencies between the activities have been identified. Remember that the preceding activity must be fully completed before work on the following activity can be started.
    Your project is divided into five major subprojects. Subproject “P” involves developing specifications for the new cell phone. Here decisions related to such things as battery life, size of the phone, and features need to be made. These details are based on how a customer uses the cell phone. These user specifications are redefined in terms that have meaning to the subcontractors that will actually make the new cell phone in subproject “S” supplier specifications. These involve engineering details for how the product will perform.
     The individual components that make up the product are the focus of subproject “D.” Subproject “I” brings all the components together, and a working prototype is built and tested.
     Finally in subproject “V,” suppliers are selected and contracts are negotiated.

Exhibit 5.13: Work Breakdown Structure and Activities for the Cell Phone Design Project

MAJOR SUBPROJECTS/ACTIVITIES	ACTIVITY IDENTIFICATION	DEPENDENCY	DURATION (WEEKS)
Product Specifications (P)
Market research	P1	—	2
Overall product specifications	P2	P1	1
Hardware	P3	P2	3
Software	P4	P3	4
Supplier specifications (S)
Hardware	S1	P4	4
Software	S2	P4	6
Product design (D)
Battery	D1	S1	1
Display	D2	S1	2
Camera	D3	S1	1
Outer cover	D4	D1, D2, D3	3
Product integration (I)
Hardware	I1	D4	5
User interface	I2	D2	3
Software coding	I3	I2	3
Prototype testing	I4	I1, I3	3
Subcontracting (V)
Suppliers selection	V1	S1 ,S2	9
Contract negotiation	V2	I4, V1	1

a. Calculate the start and finish times for each activity. (Leave no cells blank - be certain to enter "0" wherever required.)

b. Determine the minimum number of weeks for completing the project.

c. Find the activities that are on the critical path for completing the project in the shortest time.

• P1-P2-P3-P4-S1-D2-D4-I1-I4-V2

• P1-P2-P3-P4-S1-D1-D4-I1-I4-V2

• P1-P2-P3-P4-S1-D2-I2-I3-I4-V2

• P1-P2-P3-P4-S2-V1-V2

Answer 1

Solution:

Network Diagram:

a) Start and Finish Times for each activity

Start	Duration	Early Start	Early Finish	Late Start	Late Finish	Float
P1	2	0	2	0	2	0
P2	1	2	3	2	3	0
P3	3	3	6	3	6	0
P4	4	6	10	6	10	0
S1	4	10	14	10	14	0
S2	6	10	16	12	18	2
D1	1	14	15	15	16	1
D2	2	14	16	14	16	0
D3	1	14	15	15	16	1
D4	3	16	19	16	19	0
I1	5	19	24	19	24	0
I2	3	16	19	18	21	2
I3	3	19	22	21	24	2
I4	3	24	27	24	27	0
V1	9	16	25	18	27	2
V2	1	27	28	27	28	0

b) Minimum number of weeks for completing the project:

Shortest Duration for project completion is the critical path duration. Activities lying on critical path i.e P1,P2,P3,P4,S1,D2,D4,I1,I4,V2. Critical path is P1-P2-P3-P4-S1-D2-D4-I1-I4-V2 with duration 28 days.

Minimum number of weeks for completing the project is 28 days

c) Activities on critical path for completing the project in shortes duration is : Option A) P1-P2-P3-P4-S1-D2-D4-I1-I4-V2

(Explained in part b)