-
Project Time Control In Building Construction
CHAPTER ONE -- [Total Page(s) 3]
Page 2 of 3
-
-
-
In order to establish a basis from which to calculate a schedule using
the duration estimates for the activities, it’s necessary to select the
estimated start time and required completion time for overall project.
These times define overall window or envelope, of time in which the
project must be completed. The projects required completion time is
normally part of the project objective and stated in the contract. Once
the, estimated duration for each activity in the network and an overall
window of time in which the project must be completed, you have to
decide whether the activities can be done by the required completion
time.
The key to effective project time control is to measure actual
progress and compare it to planned progress on a timely and regular
basis and to take necessary corrective action immediately. The project
time control process involves regularly gathering data on project
performance, comparing with the planned performance. This process must
occur regularly throughout the project.
It starts with establishing a
baseline plan that shows how the project scope will be accomplished on
time and within the budget. Once this baseline plan is agreed with the
customer the project starts. A regular reporting period should be
established for comparing the actual progress with the planned progress.
Reporting may be daily, weekly, or monthly depending on the complexity
and the duration of the project. During each reporting period, two kinds
of data or information need to be collected.
1.2 STATEMENT OF PROBLEMS
Ackermann, Eden, Howick and Williams (2000) point out the pitfall of using 0. They are:
a) When a network is resource-constrained, there is no agreed definition of what a 'project time control ' actually is.
b)
Many effects, such as change orders, impact many activities
simultaneously. In such cases, single-activity analyses in PRC do not
really work, and more sophisticated analyses or network simulation is
needed.
c) PRC cannot take account of soft factors such as
demotivation. Disruption affects productivity in a fashion that means it
varies over time, PRC times do not usually take account of changes in
productivity, let alone when it is a variable factor.
d) project time control (PRC) does not take into account management actions to deal with delays and disruptions.
Adding resource
Adding
resource is most common methods for shortened project time. But there
are limits, such as some of activities cannot be shortened by adding
staffs and equipment and some time the relation between staffs size and
time shorten is not linear. Adding resource, you cannot achieve as your
want.
Overtime
This is the easiest way to add more labour and not
add more staffs. But need to face the challenge of team numbers'
antipathy and the low efficiency in the overtime work.
Outsourcing
This
is also a common method to shortening the project time by
subcontracting the activities. The issue is most of the time, the
subcontractor need to warm up before start their project jobs.
NPV
The problem that exists within the field of NPV is that after getting a project authorized.
There
will be no further consideration given to the project's NPV until a
post investment appraisal can be carried out. However, at this point the
damage has been done (Gardiner and Stewart, 2000, p252).
1.3 OBJECTIVE OF THE STUDY
Erel
and Raz (2000) state that the project time control cycle consists of
measuring the status of the project, comparing to the plan, analysis of
the deviations, and implementing any appropriate corrective actions.
When a project reach the construction phase, monitor and control is
critical to deliver the project success. Project monitoring exists to
establish the need to take corrective action, whilst there is still time
to take action. Through monitoring the activities, the project team can
analyze the deviations and decide what to do and actually do it
(Gardiner and Stewart 2000,p252). The purpose of monitor and control is
to support the implementation of corrective actions, ensure projects
stay on target or get project back on target once it has gone off target
(Erel and Raz, 2000,p253).
a) Do unstarted activities really have to
await the completion of other activities before they can start? If no,
start the activities
b) If an activity has to wait for the completion
of other activities, can that activity be broken down into
sub-activities and some of the sub activities completed at an earlier
date? If no, break down the activity into sub-activities and start the
urgent one at once.
Herroelen and Reyck (1999) also state that
managers have to tackle the challenging problem of scheduling activities
to minimize the project duration, in which the activities (a) are
subject to generalized precedence relations, (b) require units of
multiple renewable, non-renewable and doubly constrained resources for
which a limited availability is imposed, and (c) can be performed in one
of several different ways, refected in multiple activity scenarios or
modes.
CHAPTER ONE -- [Total Page(s) 3]
Page 2 of 3
-
