By: Ernawati Mustafa Kamal School of Housing, Building & Planning

Universiti Sains Malaysia

A project is a collection of tasks that must be completed within certain time frame, with specific cost & quality.

Estimating time of project by determining the earliest start and finish of each activity.

Finding the minimum cost schedule needed to complete the project by a certain date.

Investigating the results of possible delays in activity’s completion time.

Progress control.

Smoothing out resource allocation over the duration of the project.

Tasks are called “activities.” - Estimated completion time (and sometimes costs) are associated with each activity.

- Activity completion time is related to the amount of resources committed to it.

- The degree of activity details depends on the application and how specific is the data.

To determine optimal schedules we need to◦ Identify all the project’s activities.

◦ Determine the precedence relations among activities.

Example:

- Company A is a contractor & they need to

construct a house.

Major task they need to perform &

complete:

- Sub-structure

- Superstructure

- Internal Finishes

- Services and finishing

- External Works

Company A needs to develop a precedence relations chart.

The chart gives a concise set of tasks and their immediate predecessors.

Activity DescriptionA Piling

Sub-Structure B Pile caps and ground beams

Activity DescriptionA Piling

Sub-Structure B Pile caps and ground beams

C FrameD Upper Floors E RoofF Stairs and Ramps

Superstructure G External Walls H Windows and External DoorsI Internal Walls and Partitions J Internal Doors

C FrameD Upper Floors E RoofF Stairs and Ramps

Superstructure G External Walls H Windows and External DoorsI Internal Walls and Partitions J Internal Doors

Internal Finishes K Wall finishesL Floor FinishesM Ceiling Finishes

Internal Finishes K Wall finishesL Floor FinishesM Ceiling Finishes

Activity DescriptionN Sanitary installation

Services & Finishing O Water installationP Electrical installation

Activity DescriptionN Sanitary installation

Services & Finishing O Water installationP Electrical installation

Q Road, Paths, Pavings & SurfacingExternal Works R Landscaping and Irrigation Systems

S FencingT External drainageU External services

Q Road, Paths, Pavings & SurfacingExternal Works R Landscaping and Irrigation Systems

S FencingT External drainageU External services

From the activity description chart, we can determine immediate predecessors for each activity.

Mathematical Analysis- calculating theoretical early and late start and finish dates for all projects activities without regard for any resource limitations.

- The resulting dates are not schedule, but it indicate the time period within which activity should be schedule.

Critical Path Method (CPM)

Graphical Evaluation and Review Techniques (GERT)

Program Evaluation and Review Technique (PERT)

Bar Charts- Milestone charts- Gantt charts

Horizontal time scale is used, often divided into weeks.

Various operations comprising the project are listed vertically down the left-hand side.

The timing and duration of each operation indicated by a horizontal bar spanning the relevant period of weeks and shown on the same line as the operation it refers to.