7. OBJECTIVES
Explain the purpose and importance of network diagrams in
project planning and scheduling.
Plot and label earliest start, latest finish, and critical path in a
network diagram.
Appreciate the importance of time management and
planning in construction and project work.
8. NETWORK DIAGRAM
Every project is composed of works, activities, tasks or functions
that are related to one or the other in some manner
The main goal is to finish the project under the following
objectives
a)To complete the project at the earliest minimum time
b)To use any available manpower, equipment and other resources
c)To complete the project with a minimum capital investment
without causing undue delay
9. - PERT/CPM utilizes all resources effectively as possible
- Time is considered as the controlling factor in
Construction Management
Time versus number of manpower
Time versus number of equipment
Time versus peso
Planning and Scheduling
- Planning is a logical sequence of the job to be performed.
10. Scheduling is only secondary to planning. It is the process of
allocating calendar dates to jobs based on the approved plan.
Definition ofTerms
Critical Path - is the longest route in the network of activities
representing a project
Earliest Event – is the earliest time occurrences of an event
sometimes called Earliest Event Time or Early EventTime
Earliest Start – is an activity cannot be earlier than the event time
of the event
11. Earliest Finish – is an activity cannot be earlier than the
event time of the event
EF = ES + Duration or
EF = Early event + Duration
Latest Event – is the latest time the event sometimes
may occur without delaying project completion
Latest Finish – is an activity cannot be later than the
latest event
12. The Latest Start plus Duration is equals the Latest Finish
LS + D = LF or LS = LF – D
Total Float or Total Slack – is the span of time an activity can be
delayed after its earliest time without delaying the project completion.
LF – EF = Total Float or
LS + D – (ES + D) or
LS – ES = TOTAL FLOAT
13. Free Float – is the span of time an activity can be delayed after its
Early Start without delaying the Earliest Start of any succeeding
actual activity;
FF = ES – (ES+D)
Independent Float – is that portion of the activities Free Float
that would remain if all its preceding activities used up all their float.
14. Assume an early Start (ES = 0) for activities without predecessors
