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 $5\mathrm{.}13$: Work Breakdown Structure and Activities for the Cell Phone Design Project

MAJOR SUBPROJECTS$/$ACTIVITIES ACTIVITY IDENTIFICATION DEPENDENCY DURATION $($WEEKS$)$

Product Specifications $($P$)$

Market research P$12$

Overall product specifications P$2$ P$14$

Hardware P$3$ P$23$

Software P$4$ P$33$

Supplier specifications $($S$)$

Hardware S$1$ P$43$

Software S$2$ P$45$

Product design $($D$)$

Battery D$1$ S$14$

Display D$2$ S$13$

Camera D$3$ S$14$

Outer cover D$4$ D$1,$ D$2,$ D$34$

Product integration $($I$)$

Hardware I$1$ D$42$

User interface I$2$ D$24$

Software coding I$3$ I$24$

Prototype testing I$4$ I$1,$ I$34$

Subcontracting $($V$)$

Suppliers selection V$1$ S$1,$S$210$

Contract negotiation V$2$ I$4,$ V$12$

Calculate the earliest and latest start and finish times for each activity.