Because of the uncertainty involved, the schedule is
reviewed regularly, and it is often revised while the project is in progress.
It continues to develop as the project moves forward, changes arise, risks come
and go, and new ones are identified. The schedule essentially transforms the
project from a vision to a time based plan.
Schedules also help you do the following:
They provide a basis for you to monitor and
They help you determine how best to allocate
resources so you can achieve the project goal.
They help you assess how time delays will impact
You can figure out where excess resources are
available to allocate to other projects.
They provide a basis to help you track project
Project managers have a variety of tools to develop a
project schedule from the relatively simple process of action planning for
small projects, and the use of Gantt Charts.
Outlined below, the key tools you will need for schedule
You need several types of inputs to create a project
Personal and project calendars- understanding
working days, shifts, and resource availability is critical to completing a
Description of project scope- from this, you can
determine key start and end dates, major assumptions behind the plan, and key
constraints and restrictions. You can also include stakeholder expectations,
which will often determine project milestones.
Project risks- you need to understand these to
make sure there’s enough extra time to deal with identified risks and with
unidentified risks. Risks are identified with thorough Risk Analysis.
Here are some tools and techniques for combining these
inputs to develop the schedule:
Schedule Network Analysis- this is a graphic
representation of the project’s activities, the time it takes to complete them,
and the sequence in which they must be done. Project management software is
usually used to create these analyses, Gantt Charts and PERT charts are common
Critical Path Analysis- this is the process of
looking at all of the activities that must be completed, and calculating the
critical path, to take so that you’ll complete the project in the minimum
amount of time. The method calculates the earliest and latest possible start
and finish times for project activities, and it estimates the dependencies
among them to create a schedule of critical activities and date.
1.1 Definition of Quantity Survey
Quantity survey is a schedule of quantities
of all the items of work in a building.
1.2 Data Required for the Preparation of an
Estimate or Quantity Survey
Complete and fully dimensioned drawings (i.e.
plans, elevations, sections and other details) of the building or work in
question are required.
Detailed specifications, giving the nature,
quality and class of work, materials to be used, quality of the material, their
proportions, and method of preparation are required.
The rates of different work, materials to be
used in the construction, wages of different categories of labor (skilled or
unskilled) and cost of transportation charges should be available for preparing
an estimate of work cost.
1.2.4 Actual Finished Work
Quantities can be calculated from the actual
work done in the project site.
– The quantities mainly can be calculated as:
Quantity = Length × Width × (Height or
Quantity = Area of cross-section × Length,
Quantity = Length × Width,
Quantity = Length.
Quantity = Number of Units.
Quantity = Weight.
1.3 Importance of Quantity Survey
1. Quantity survey is essential to estimate
before the construction starts the probable cost of construction for the
complete work. The construction cost includes cost of materials, cost of
transportation, cost of labor, cost of scaffolding, cost of tools and plants,
establishment and supervision charges, cost of water, taxes and reasonable
profit of the contractor, etc. The estimate is required in inviting tenders for
the works and to arrange contract for a complete project.
2. Quantity survey is required to estimate
the quantities of the various materials required and the labor involved for
satisfactory completion of a construction project.
3. It is also useful to check the works done
by contractors during and after the execution. Also the payment to the
contractor is done according to the actual measurements of the completed part
of each item of work.
4. A complete quantity survey or estimate is
useful to provide useful advice to clients on:
(i) Valuation of properties (land and
building) for sale, purchase and mortgage etc.
(ii) Fixation of standard rent.
(iii) For insurance and claim for damages in
(iv) For the process of resolving disputes by
referring to a third party.
1.4 Types of Estimates and Quantity Survey
1.4.1 Preliminary or Approximate Estimate
This is to find out an approximate cost in a
short time. It is used to give an idea of the cost of a proposed project. This
estimate helps the client or sanctioning authority to make decision of the
The approximate cost is prepared from the
comparison with similar works. The approximate cost can be found by using
methods that depends on the area or cubic content of a building and then
multiplying this by an estimated rate for the unit of the area or cubic
content. Approximate quantities of materials and labor required per m2 of the area for a proposed building also can be found.
1.4.2 Detailed Estimate
After getting the administrative approval,
this estimate is prepared in detail prior to inviting of tenders.
The whole project is divided into sub-works,
and the quantities of each sub-work are calculated separately. The dimensions
of the required work are taken from the drawings of the project.
1.4.3 Quantity Estimates
This is a complete estimate of quantities for
all items during project implementation.
1.4.4 Revised Estimate
Prepared if the estimate exceeded by 5% due
to the rates being found insufficient or due to some other reason.
1.4.5 Maintenance Estimate
Estimating required quantities and cost of
work to maintain a structure (road, building, etc.)
Contract is an agreement between two or more
parties creating obligations are enforceable or recognizable at law. It
establishes an obligation of each party to fulfill what it is agreed to
1.5.1 Obligations of the employer
1. Appointing of the engineer to administer
2. Provision of the site
3. Provision of information, permits, and
4. Providing funds and making payments in
accordance with the contract
5. Participation in consultations with the
engineer to agree matters on claims or conflicts between parties.
1.5.2 Obligations of the Contractor
1. Execution and completion of the works and
remedying any defects therein.
2. Provision of:
a. Labor, materials, plant, and equipment
b. Preparation of progress report
c. Works program for execution, and updating
it whenever required
d. Setting out of the works
e. Measurement and/or assisting the engineer
to do so
f. Records of his personnel and equipment
g. Sample of materials specified
h. Testing and re-testing
i. Temporary works
j. Facilities for other contractors working
on the site
k. Keeping the site clean, and remove rubbish
3. The contractor is required to:
a. Sign the contract when he is called to do
b. Obtain and submit securities, guarantees,
and insurance policies
c. Ensure that his representatives will be
available on site at all times
d. Prepare and submit the contractor’s
document, including “as built drawings” and manuals of operation and
e. Attend to the engineer’s instructions
f. Provide access to the employer’s personnel
to enter the site
g. Prepare and submit payment statement and
h. To uncover works for inspection when
i. Rectify (Correct) defective works
j. Secure or compensate the employer against
k. Submit notices to the engineer whenever he
encounters circumstances that may cause future claims
l. Getting approval before assigning
sub-contractors or partners of the works
m. Respond for consultation with the engineer
4. Comply with the applicable laws, labor law
and other local regulations.
1.5.3 Role of the Engineer
Usually the employer will enter into a
consultancy agreement with the engineer to design and/or supervise the works.
The engineer shall have no authority to amend
Engineer role can be:
1. as the employer’s agent:
a. Administration of the contract – dealing
with the procedures, provision of information and interpretations, issuance of
variations, approval of samples, etc.
b. Cost accountancy and payments
2. as a supervisor:
The engineer must ensure that the work is
being performed to fulfill the contract documents.
3. as a certifier:
The engineer is required to certify or
approve the payments that should be paid by the employer to the contractor.
Those payments should be made periodically, mostly on monthly basis, and should
depend on the quantity of works finished by the contractor.
4. as a determiner:
The engineer must act as a mediator to help
the parties towards agreement in issues such as claims for reimbursement of
costs or extension of time.
5. Issuance of instructions and variations
Include: issuance of additional or modified
drawings, actions in relation to defective works, issuance of clarifications,
giving approval, and ordering variations.
1.6 Types of Contracts
1.6.1 Measured or Unit rate Contract
In this type of contract, the price is
computed by multiplying quantities of work executed by the unit rate offered by
the contractor in his tender. The rates are usually set out in the Bill of
contracts often used where there are significant changes in the quantities or
when there are certain reasonable differences of the quantities accepted by all
the parties, then the contract can be paid for by multiplying the actual
measured quantities by the unit rates.
Suitability: This type of contract is widely used in the execution of large
projects financed by public bodies or governments. It also suits the works
which can be split into separate items and the quantity of each item could be
estimated with reasonable accuracy.
The employer pays for the actual work executed.
The contractor usually allows for a certain margin of variation, with a clear
mechanism for valuation of such variations.
The engineer / employer has liberty to provide some drawings during the
execution of the project, after award.
The employer cannot be absolutely sure of the total cost of the project until
the whole work is completed. In case the quantities in the BOQ are inaccurate
or roughly approximated, the value of the work may vary considerably. The
contractor may try to offer an unbalanced tender on the basis of his
anticipation of the uncertainty of quantities of certain items.
Both the engineer and the contractor have to do considerable computations and
book-keeping during the progress of work.
Extra works or varied items of work are often a source of conflict. The
contractor may press for higher rates than he would have tendered for in the
1.6.2 Lumpsum contract
In a lumpsum contract, the contractor agrees
to carry out the entire work as indicated in the drawings and described in the
specifications, for a specified fixed lumpsum amount.
Sometimes, the contract makes provisions to
adjust the “lump sum” allowing for extra work and limited variations.
Normally, a bill of quantities is not usually
included, and if included it does not form part of the “Contract Documents”,
but may be used just for guidance.
Instead, a schedule of rates may be of value
to evaluate the cost of extras or omissions.
l. From the employer’s stand point, and if no
extras are contemplated, the tender sum tells him the exact cost of the
project. Sometimes the employer will be working within a tight margin of budget.
2. From the contractor’s stand point, because
the design will often be prepared by him, the contractor can gain through
proper planning and efficient management to increase his margin of profit
and/or to control timing.
3. Both parties need less number of staff for
book-keeping accounting and measurement.
l. In lump sum contracts, there should be a
complete set of plans and specifications, or what is called “Employer’s
Requirements” which should be sufficiently detailed.
2. Variations in lump sum contract may
trigger conflicts about whether or not a particular item of work falls within
the agreed scope of work, and whether there has been a variation to such scope.
3. This type of contract will not be suitable
for works with scope and nature that cannot be predicted accurately in advance.
The outcome will be unfair for the contractor to assume all risks and
uncertainties, or for the employer to pay a higher cost.
1.6.3 Cost-plus contract
This type of contract differs from both the
measured and the lumpsum contract in that the employer agrees to pay the
contractor for the actual cost of the work plus an agreed percentage of this
actual cost to cover overhead and profit.
The contractor agrees to execute the works
based on the drawings and specifications and any other information that will be
provided to him from time to time during progress of the works.
The percentage to be paid should not be
applied on the costs of salaries of the contractor’s staff, whether on-site or off-site.
1. Early completion of the work – The work
can be started even before the design and estimates are prepared. Decisions can
be taken speedily, and flexibility allows adoption of alternates for
construction to suit the Employer’s Requirements.
2. The quality of the work can be assured.
The contractor is induced to perform the work in the best interest of the
3. No conflicts will be anticipated as to
extras or omissions.
1. The final cost to the employer cannot be
2. Both parties have to do a lot of
accounting and book-keeping regarding labour; purchase of materials and plant
and use of equipment.
3. The contractor has no incentive to economize
or finish the work speedily.
In spite of some drawbacks in certain cases,
this form of contract can be used suitably for:
a- Emergency works that require speedy
construction and where no time is available to prepare drawings for it.
b- Construction of special or expensive
projects, such as palaces, where the cost of the work is of no consequence but
the materials and workmanship to be purchased are just to suit the choice and
taste of the employer.
An alternate to the cost-plus contract is the
cost-plus fixed fee contract, where the contractor will be paid for the actual
cost of construction plus a fixed amount of fees for his overhead and profit.
The fee does not fluctuate with the actual cost of the project. This factor may
overcome the possible drawback of the cost-plus contract.
1.6.4 Construction Management Contract (C.M.)
In this type of contract, the employer
engages a specialized construction manager (C.M.) to provide administrative
service for him and manage the work on his behalf. The (C.M.) has full control
(Cost and Time), on the budget and
programming, and is usually paid on a staff-reimbursement basis.
The (C.M.) assists in choosing the design
consultant and the various contractors for a project divided into packages
(structural, finishes, electro-mechanical, etc.).
The technical role is kept with the
design-professional, but as to control, coordination, certification and dispute
resolution, the (C.M.) normally possesses
the major role.
There are numerous challenges facing today’s
construction manager. Some are new to the industry, and some are
centuries old. Many of these challenges are a direct result of construction
operations, while others a result of indirect, peripheral activities. A
surprising number of challenges are not construction issues but must be
addressed and managed by the construction manager (CM) to ensure project
success. Some of the construction issues include workforce considerations,
safety, time constraints, and the changing nature of the work. Non-construction
challenges that CMs face that are part of the business landscape include legal
issues, government regulations, environmental concerns, and socio-political
pressures. It is critical that the CM understands the demanding realities that
he or she faces in the planning and control of construction operations.
projects represent a unique set of activities that must take place to produce a
unique product. The success of a project is judged by meeting the criteria of
cost, time, safety, resource allocation, and quality as determined by the
owner. The purpose of Project Management is to achieve goals and
objectives through the planned expenditure of resources that meet the project’s
quality, cost, time, scope, and safety requirements. The CM must
control, deflect, or mitigate the effects of any occurrence or situation that
could affect project success.
CM faces many challenges, stemming from a variety of sources. These challenges
can have an impact on project success. CMs must be keenly aware of the risks
and implications of these challenges. The challenges listed in this report
include situations and conditions that must be proactively managed by the CM to
ensure project success. Many of these challenges are a direct result of
construction operations, while others are a result of indirect, peripheral
activities. Construction issues include workforce considerations, safety, time
constraints, and the changing nature of the work itself. Non-construction
challenges that CMs face that are part of the business landscape include legal
issues, government regulations, environmental concerns, and socio-political
CMs understand and navigate through these realities. CMs that are able to master
obstacles gain a competitive advantage. Excellent CMs transform risks into
opportunities. Excellent CMs understand the business, legal and social aspects
of construction. They act as responsible stewards of the environment and
observe all applicable laws and ethical practices. Excellent CMs value the
people they employ and work to ensure their safety and promote their
well-being. Excellent CMs proactively manage operations to achieve the
project’s quality, cost, time, and scope requirements.
excellent CM strives to avoid and resolve conflict and promote harmony among
all project stakeholders. The excellent CM adapts to the changing business,
social, and legal environment, and leads the organization through the
challenges it faces.