Optimizing Ground Works and Plaster Works for Construction Project

This document provides insights on optimizing ground works and plaster works for a construction project. It covers accurate measured quantities, productivity constants, tradesman hours, suitable gang size, and time needed to complete the tasks. It also discusses ways to compress the project schedule and reduce overall time and cost. The document is suitable for construction management courses and professionals in the field.

Running head: ASSESSMENT 5
CPCCBC5003A ASSESSMENT 5
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ASSESSMENT 5 2
CPCCBC5003A Assessment 5
Question 1
The two tasks selected are ground works (bulk excavation to site) and plaster works (cement
render to internal).
i) Ground works
a. Accurate measured quantities
From the preliminary estimate file, the measured quantity for ground works (bulk
excavation) is 4,500m2. This includes the area of soil, rocks or vegetation materials excavated
from the site and carted away or used as backfill. The volume of bulk excavation can be obtained
by multiplying 4,500m2 with the average depth of excavation. The depth of excavation in this
task is 1.2m. Thus the volume of bulk excavation is: 4,500m2 x 1.2m = 5,400m3
b. Appropriate productivity constants
Ground works productivity constant includes productivity constant for excavating the top soil
(over area), backfilling and compacting the area one layer after the other. The productivity
constant in this task includes that for labour for storing, transporting, delivering and disposing
the excavating materials.
Productivity constant for ground work (bulk excavation not exceeding 1.5m) = productivity
constant for excavating over area + backfilling, levelling, trimming and compacting (Mishra,
2018).
= 0.62 (labour for excavating over areas) + 0.25 (labour for backfilling, leveling and compacting)
= 0.87

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The units for productivity constant is labour days per unit. In this case, it means that it will take
0.87 labour days to excavate 1m3.
c. Tradesman hours
As aforementioned, the productivity constant of 0.87 means that it will take 0.87 labour days to
complete 1m3 of bulk excavation.
1m3 = 0.87 labour days
5,400m2 = labour days?
5,4 00 m2 x 0.87 labour days
1 m2 =4,698labour days
It is assumed that a working day has 8 hours. Therefore the tradesman hours in 4,698 labour days
is calculated as follows:
1 labour day = 8 hours
4,698 labour days = hours?
4,698 labour days x 8 hours
1 labour day =37,584 trademan hour s
d. Suitable gang size
The gang size that is suitable for this task is 16. This gang size comprises of one supervisor,
one excavator operator, two loaders, four dumper drivers and 8 unskilled labourers.
e. Time needed to complete the task

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The time needed to complete the bulk excavation work will largely be determined by the
productivity of the two excavator operators. Assuming that the productivity of one excavator is
100m3/hour and that the average operating time of an excavator is 4 hours a day.
From the gang size above, there is one excavator operator. This means that the volume of soil
excavated by one excavator working 4 hours a day is:
1 x 4 hours x 100m3/hour = 400m3
But the total volume of bulk excavation is 5,400m3. Therefore the number of days needed to
excavate 5,400m3 of soil is calculated as follows:
400m3 = 1 day
5,400m3 = days?
5,400 m3 x 1 day
40 0 m3 =13 . 5 days 14 days
In addition to excavation, there are other tasks such as backfilling, levelling, trimming and
compacting, which are estimated to take a total of 4 days. This means that the total time needed
for ground works is:
14 days + 4 days = 18 days.
f. Task review
The predecessor of ground works is preliminaries, which include numerous activities, some
that will be undertaken as the project continues. The sequence of the task is appropriate because
it comes after necessary preceding activities have been completed such as demolition, site
clearing, site fencing, rubbish removal, temporary services installation, construction of

ASSESSMENT 5 5
accommodation facilities, and acquisition of necessary approvals. The duration allowed for the
task is 20 days while the time needed to complete this task (as calculated in part e above) is 18
days. One important change that should be considered is using an excavator with a higher
production capacity or using two excavators. This will significantly reduce the time needed to
complete ground works, which can help reduce completion time and overall cost of the project.
ii) Plaster works – rendering
a. Accurate measured quantities
The measured quantity for internal cement rendering is 5,800m2.
b. Appropriate productivity constants
Plaster works productivity constant includes the productivity constant for preparing the
mortar and applying it on the walls, which is calculated as follows:
= 0.06 (mason) + 0.10 (labour) = 0.16 labour days/m2.
c. Tradesman hours
The productivity constant of 0.16 means that it will take 0.16 labour days to complete 1m2 of
plaster work.
1m2 = 0.16 labour days
5,800m2 = labour days?
5,8 00 m2 x 0. 16 labour days
1 m2 =9 28 labour days
If a working day has 8 hours the3n the tradesman hours in 928 labour days is calculated as
follows:

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1 labour day = 8 hours
928 labour days = hours?
9 28 labour days x 8 hours
1labour day =7,42 4 trademan hours
d. Suitable gang size
The gang size that is suitable for plaster work is 17. This gang size comprises of one
supervisor, 8 masons and 8 unskilled labourers.
e. Time needed to complete the task
The time needed to complete the plaster work will largely be determined by the productivity
of the masons. If the productivity of one mason is 30m2/day, it means that that the total wall area
that will be plastered by 8 masons in a day is:
8 x 30m2 = 240m2 per day
Thus the time needed to plaster 5,800m2 is:
240m2 = 1 day
5,800m2 = days?
5,8 00 m2 x 1 day
2 4 0 m2 =24 . 2 days 25 days
f. Task review
The predecessors of plaster work include preliminaries, ground works, masonry works,
concrete works, and electrical works. Therefore the sequence of this task is appropriate because
it will come after essential preceding works have been completed. The duration allowed for

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plaster work is 31 days while the time needed to complete this task, from the calculation above,
is 25 days. This means that the time allocated for plaster work is adequate. However, one
recommended change is to increase the gang size to 10 masons and 10 unskilled labourers. This
will help to reduce the time needed to compete the plaster work thus reducing the completion
time and cost of the project.
Question 2
The program provided has included all the project activities hence it is suitable for
successful completion of the project. The sequence of the tasks is also appropriate and each task
has been allocated adequate time. This is very important in avoiding delays cause by inadequate
time to complete individual tasks. One of the drawbacks of this program is that it is linear
meaning that a task can only be started after all its predecessors have been completed. In a
parallel program, tasks cannot be fast-tracked or completed in a parallel manner (Agrama, 2011).
This project also has numerous repetitive tasks hence a linear program is not a suitable option
(Kannan & Senthil, 2014). Therefore if this program is used, project delivery period will be very
long. There are several activities that can be done concurrently to reduce completion time and
cost of the project.
From the calculation of time needed to complete ground and plaster works, it is evident
that the time allocated for various activities in the program is not very accurate. In the two
calculations, time allocated was greater than time needed to complete the tasks. There is need to
use modern methods and tools to accurately determine the time needed to complete the tasks in
this project. Accurate scheduling will significantly reduce the time and cost of completing the
project (Zha & Zhang, 2014).

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This program could also have been presented in a better way using modern tools such as
Gantt chart. This is a tool that makes a program to look logical and easier to interpret. Gantt
chart shows the sequence, duration and interconnection between tasks. It also helps in identifying
tasks that can be done concurrently to ensure maximum utilization of labour and equipment.
Therefore the recommended changes are to recalculate the tine needed for each task, prepare a
parallel or non-linear program and create a Gantt chart for the project. All these changes will
improve allocation and utilization of resources thus reducing both time and cost of completing
the project.
Question 3
Proper scheduling is very essential in successful completion of any construction project.
In most cases, project managers create optimistic schedules, which sometimes are not realistic.
To be on a safer side, it is recommended to create a more realistic schedule but this is largely
hindered because of optimism (Prater, Kirytopoulos, & Tony, 2017). The schedule that has been
provided for this project is optimistic. This is mainly because the schedule is linear and the
project manager is hoping that every activity will be completed as scheduled so that it does not
affect the succeeding activities. A linear schedule or program is only created if the project
manager is optimistic that all activities will be completed as planned even though this is not
always the case. Every activity in the schedule provided has been allocated adequate time with
hopes that the activity will be completed within this time so that the next activity can be started
as scheduled. However, uncertainties are inevitable in construction industry (Liu, 2012), hence
the project is still exposed to uncertainty despite the schedule being optimistic. The schedule can
be made more realistic by employing an independent professional to improve it.

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Question 4
I would not accept this schedule and provide it to my client or architect for several
reasons. First, the presentation of the schedule is not professional. There are several more
advanced tools and software, such as MS Project, which can be used to make a more presentable
schedule. Therefore I would create a Gantt chart, which is a more professional way of presenting
a project schedule. Second, I would recalculate the duration for each activity. The two
calculations done showed that there was inaccuracy in calculating the duration allocated for each
activity. Third, I would create a non-linear (parallel) schedule instead of a linear program. This
will help the client save time and cost of completing the project. Last but not least, I would strive
to ensure that the schedule prepared is more realistic than optimistic. This will make it easier to
implement in real life situation.
Question 5
a. Impacts of working overtime each day
By working overtime each day, it will take less than 18 and 25 days to complete the ground
works and plaster works respectively. Working overtime each day will also reduce the cost of
completing these tasks because earlier finish will result to a reduction in the number of days and
cost of leasing equipment and the cost used to run the site every day. This is because more work
will be done every day than as it was calculated before. Hence working overtime each day will
reduce the overall delivery time and cost of completing ground works and plaster works.
However, this will be realized only if the production rate of equipment and workforce is not
affected by the overtime.
b. Working 6 days per week

ASSESSMENT 5 10
The impact of working 6 days per week will have similar impacts as working overtime each
day. This is because both ground works and plaster works will take more than two weeks to
complete. Working 6 days instead of 5 days per week means that more work will be done per
week than as it was calculated before. As a result, this will significantly reduce the time and cost
of completing ground works and plaster works. Nevertheless, this can only be realized if the
production rate of the machines, equipment and personnel remain the same.
c. Other ways of compressing project schedule
There are several other ways of compressing the project schedule. The two main approaches
are fast-tracking and crashing. Fast-tracking basically means creating and using a parallel
schedule instead of linear schedule. This will ensure that activities are done concurrently, where
applicable, thus ensuring maximum utilization of resources. Crashing involves allocating more
necessary resources to each activity. In this case, the project schedule could be compressed by
purchasing or leasing more equipment and tools needed for ground works and plaster works,
such as excavators, dumpers, loaders, mortar mixers, excavator operators, dumper and loader
drivers, masons, unskilled labourers and supervisors. Other techniques of compressing the
project schedule include: prefabrication, improved training and supervision, hiring qualified
workers, ensuring timely delivery of materials, ensuring that equipment are maintained
appropriately, ensuring safety of workers so as to prevent safety risks and hazards, motivating
workers by rewarding them accordingly for earlier or timely completion of assigned tasks, and
use of innovating methods to complete the ground works and plaster works.

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Works Cited
Agrama, F. (2011). Linear projects scheduling using spreadsheets features. Alexandria Engineering
Journal, 50(2), 179-185.
Kannan, S., & Senthil, R. (2014). Production based scheduling method for linear construction in road
projects. KSCE Journal of Civil Engineering, 18(5), 1292-1301.
Liu, J. (2012). Schedule Uncertainty Control: A Literature Review. Physics Procedia, 33(1), 1842-1848.
Mishra, G. (2018). Labor Requirement for Various Construction Works. Available from
https://theconstructor.org/tips/labor-requirement-building-construction-works/6906/
Prater, J., Kirytopoulos, K., & Tony, M. (2017). Optimism bias within the project management context: A
systematic quantitative literature review. International Journal of Managing Projects in Business,
10(2), 370-385.
Zha, H., & Zhang, L. (2014). Scheduling Projects with Multiskill Learning Effect . The Scientific World
Journal, 2014(1), 1-7.