ASST. PROFESSOR um Shree Swami atmanand saraswati inst. of technology, surat
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Module :-5 project scheduling and resource levelling
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for the subject offered in GTU in the final year (8th semester), construction management
final year
Module:- 5 project scheduling and resource leveling
Module :-5 project scheduling and resource levelling
1. PREPARED BY:-
Karm Balar
Asst. Prof.
S.S.A.S.I.T.
S.S.A.S.I.T G.T.U
SHREE SWAMI ATMANAND SARASWATI
INSTITUTE OF TECHNOLOGY, SURAT
Construction management
3. The scheduling of activities, so that none of the precedence
relationships are violated and none of the resource availabilities
are exceeded, is a difficult task and can result in a number of
combinations of possible early start and late start schedules.
In literature, scheduling problems with limited resources is
classified as large combinatorial problem.
A number of programs based on some rules of thumb (also called
heuristic) have been developed to solve such problems.
These heuristic programs for resource scheduling can be broadly
classified under two categories: (1) Resource leveling and (2)
Resource allocation
Introduction
4. The resource allocation procedure mainly consists of two activities:
(i) Resource smoothing
(ii) Resource levelling.
Resource Leveling and Resource Smoothing are two resource optimization
techniques. Resource Leveling is performed to balance the demand and
supply of resources. Resource Smoothing is performed to achieve a more
uniform resource utilization over a period of time. Resource Leveling may
change the critical path of the project, whereas Resource Smoothing does
not.
Methods of resource allocation
5. Resource smoothing
Resource Smoothing: Resource Smoothing is a resource optimization
technique in which the Project Manager adjusts the timing of different
activities so that the requirement for resources does not exceed a certain
pre-defined limit. The objective is to complete the work by the required
date while avoiding peaks resource demand.
The intelligent utilization of floats can smoothen the demand of resources
to the maximum possible extent is called resource Smoothing. In other
words, activities may only be delayed within their free and total float.
6. The resource smoothing is applied in such a way that the total project
duration remains the same i.e. there is no change in the total duration of
the project. First, the periods of minimum demand for resources are
determined or located and the activities are shifted according to the
availability of float and requirement of resources. Thus the intelligent use
of floats can smoothen the demand to the maximum possible extent. This
type of resource allocation is known as resource smoothing
7. Resource leveling
Resource Leveling is a resource optimization technique in which the
Project Manager adjusts the start dates and finish dates of different
activities in order to balance the demand for resources vs available supply.
If the demand of a resource is more than its availability, then the only
alternative is to delay the activity having maximum float. This process is
called resource levelling. If there are more than one activities requiring
the same amount of resources, in that case activity having minimum
duration is chosen for resource reallocation. Resource levelling is
adopted in case there is restriction on the availability resources
8. Resource levelling, Scenario A:
For example, if there are two task on project network diagram and they are
scheduled on the same time period and both required the same resource,
“X”.
Task A is on critical path, Task B is on non-critical path which means
which has float.
Further assume, the task A is high priority task than the task B.
In this situation, if we perform resource levelling, the project schedule or
critical path may or may not change.
If the levelling delay within the free or total float the project schedule will
not change otherwise it will get changed.
Resource levelling, Scenario B:
For example, if both task A and B are on critical path and they are
scheduled on the same time period and required the same resource, “X”.
If we perform resource leveling in this situation then the project schedule or
critical path will surely get changed.
It doesn’t matter which task of the two are high-priority than other.
10. Scheduling is a process for setting in order the various planned activities by fixing the
starting and finishing dates to each part of the work in such a manner that the whole
work should be done in an orderly and systematic way.
For example, a railway map will show a passenger, the route by which he will travel from
one place to another and stations along that route. But the time table will give him the
time element that is the hour when his journey will begin, the time at which the train will
reach at various stations and also the total time that will be required to reach the
destination.
In the same way the planning department will have to frame a time schedule for a
project which will assign definite timings for individual constructional operations
leading to finished product.
SCHEDULING
11. 1) Construction schedule
2) Staff schedule
3) Labor schedule
4) Material schedule
5) Financial schedule
6) Equipment schedule
7) Invoice schedule
8) Estimation of direct and indirect costs
Schedules derived from project schedule
16. The main objective of network planning is to complete the job within the stipulated
time at minimum cost. At times it becomes necessary to accelerate the completion of
work. This be made possible only by reducing the duration of critical activities. The
duration of critical path can be reduced by the deployment of additional resources e. g
additional labour, shuttering, centering etc., which again increases the cost.
While exploring the possibility of accelerating project completion by arranging additional
critical activities, the following questions require careful consideration.
To what extent the project duration be reduced ?
What is the lowest cost for reducing the project duration to the specified date?
What is the project duration for which the total project cost is the lowest?
Cost time analysis provides answers to these questions. The durations of critical
activities may be reduced in two ways (i) by deploying more resources for early
completion of such activities. (ii) by relaxing the technical specifications for such
activities.
TIME - COST TRADE OFF
17. If the duration is made longer, cost will be reduced. on the other hand, reducing the
project duration would increase the cost of the project. A decision on this will depend on
whether the commitment of additional resources and expenses is worthwhile.
The Optimum duration will be one which gives the most economic cost for completing
the project. In CPM there are two time cost estimates for each activity:
1. Normal estimate : In normal estimate, highlighting on cost, time being associated
with minimum cost.
2. Crash estimate : In crash estimate emphasis is given to absolute minimum time
required to complete the job. The necessary cost to complete the project with in the
minimum time is provided.
18. Updating can be defined as planning and programming of the
remaining portion of an activity job, by introducing the latest
information available.
At the end of day of work, the activities of the project must either be
completed, in progress or they may not have started yet.
Some of the activities may not have achieved the required percentage
of progress, which was planned to have achieved on the day of
updating.
Updating
19. As far as progress is concerned, three possibilities exists:
i) Some or all activities are progressing as per schedule.
ii) Some or all activities are ahead of schedule.
iii) Some or all activities are behind schedule.
If all activities are progressing as per schedule, there is no need for
updating the
network. But, in case of activities are behind schedule, the process of
updating is required to revive the time schedule of various activities on
the arrow diagram. Such revision is known as updating.