Object
of Scheduling
Scheduling means putting the plan on calendar basis. A
project network shows the sequence and interdependencies of activities, their
time durations and their earliest and latest completion time, but this needs to
be scheduled to determine commencement and termination dates of each activity,
using optimum resources or working within resource constraints. A time schedule
outlines the project work program, it is a time table of work.
Scheduling
Procedure
Scheduling methodology varies with the planning technique
and the nature of task. Tool kit containing commonly used techniques for
planning, scheduling and monitoring. Simple projects can be scheduled using bar
chart methodology. Line-of-Balance (LOB) technique is widely accepted for
scheduling repetitive works projects. Network scheduling methodology is
suitable for all types of projects. There are many other scheduling techniques.
Method of presentation of a schedule depends upon the technique used for
scheduling. Generally, all scheduling techniques use time scale along
horizontal axis. This time scale for most of the schedules, uses ‘week’ as the
unit of time and the weeks are then related to calendar dates. Each techniques
has its merits and demerits. But ultimately schedules are best presented in the
bar chart form for case of comprehension and communication. These bar charts
are supplemented with appropriate planning technique for monitoring time
progress. It is mentioned that scheduling is not an automatic mechanical
process, but it needs work experience to schedule the work.
The scheduling procedure depending upon type of
project can be broadly divided into two categories:
·
Scheduling
non-repetitive network based projects.
·
Scheduling
repetitive project using line of balance techniques.
Procedure
for Scheduling Network-based Plan
·
Outline
scheduling constraints
·
Design scheduling
calendar
·
List activities
in order of sensitivity
·
Draw earliest
start time schedule
·
Determine
resource optimization criteria
·
Schedule critical
activities
·
Schedule
non-critical activities
·
Validate time
objectives
·
Schedule other
resources
·
Scheduling within
resources constraints
·
Scheduling
repetitive works projects
Some
illustrations of scheduling network based projects/tasks are given below:
·
Time limited Site
Development Project
·
Resource limited
Site Development Project
·
Manpower
optimised education building project
Procedure
for Scheduling Repetitive Project Using Line-of-Balance Technique
·
Outline
scheduling constraints
·
Tabulate
scheduling data of a unit work cycle
·
Prepare a logic
diagram of a unit work cycle
·
Chart scheduling
calendar
·
Prepare Earliest
Start Time schedule
·
Analyse Earliest
Start Time schedule
·
Prepare optimum
schedule leaving adequate buffers
·
Draw
Line-of-Balance work schedule
Some
illustration of scheduling repetitive projects using line of balance techinques
are given below:
·
Line-of-Balance
Residential Building foundation
·
Line-of-Balance
Residential Building Finishes schedule
·
Residential
Buildings Monthly Work Targets
The schedule of work serves many purposes: it
simplifies the project time plan by putting it on a calendar basis; it verifies
fulfillment of time objectives; it aids in optimizing resources; it evaluate
implications of resources constraints, and it enables forecasting of input
resources, expenditure and income. These resource forecasts cover manpower,
materials, machinery, sales-income and cash-flow.
Time
Planning Techniques
A project time plan depicts the sequence of
accomplishment of the planning components plotted against project time scale.
These components include activities and events. Time planning techniques are
used to put these components on the time scale. The symbolic representation of
these plan components varies with each planning technique.
There is a large variety of time planning techniques.
The commonly known techniques are bar charts, network analysis, line of balance
technique and linear program charts.
Selection of planning technique from the techniques
tool-kit, depends upon the nature of the project or sub-project. Time plan of
simple projects, where activities and their logic can be visualized mentally,
can be plotted directly on bar charts. The complex projects are best planned
using network analysis techniques. These can then be scheduled to develop the
time scale network schedule.
In case of
projects having repetitive works, the line of balance techniques is used to
depict graphical schedule of activities. Roads, airfields and similar
linear-type construction project can be planned in the form of linear
programming charts to represent activity location, rate of work and time
schedule.
