Time cost trade off with primavera (real case)

Time Cost Trade-Off
Schedule Compression
Eng. Ahmed Said Refaei

‫عليكم‬ ‫السﻼم‬
‫م‬/‫رفاعي‬ ‫سعيد‬ ‫أحمد‬
•‫دفعة‬ ‫مدني‬ ‫مهندس‬١٩٩٣‫م‬
•Planning & Project Control Manager
•IPMA-Certified Level C
•ASPMEXP-Member
•MBA‫اﻷعمال‬ ‫إدارة‬ ‫في‬ ‫ماجستير‬-‫كاليفورنيا‬ ‫جامعة‬.
•‫المشروعات‬ ‫ادارة‬ ‫ماجستير‬ ‫يدرس‬"‫التشييد‬ ‫مشروعات‬ ‫تمويل‬ ‫تخطيط‬“-‫حلوان‬ ‫جامعة‬.
•‫السعودية‬ ‫و‬ ‫قطر‬ ‫و‬ ‫بمصر‬ ‫المقاوﻻت‬ ‫شركات‬ ‫في‬ ‫الهندسية‬ ‫المناصب‬ ‫من‬ ‫العديد‬ ‫في‬ ‫تدرج‬
•)‫تنفيذ‬ ‫مهندس‬-‫مشروع‬ ‫مدير‬-‫إحتياجات‬ ‫مدير‬-‫والمتابعة‬ ‫التخطيط‬ ‫مدير‬(
•‫صفحة‬ ‫مؤسس‬/‫موقع‬Project Management Practices
•‫فى‬ ‫العمل‬ ‫ورش‬ ‫من‬ ‫بالعديد‬ ‫قام‬:-
•-‫المشروع‬ ‫مخاطر‬ ‫إدارة‬.-‫التشييد‬ ‫بناء‬ ‫عناصر‬ ‫تكلفة‬.
•-Managing Profitable Projects.
•- Critical Chain Management
Eng. Ahmed Said 10/9/2017 ٢

Topics:
1. Introduction
• What is schedule acceleration and compression?
• Why Accelerate a Project?
• Who is responsible?
2. Projects Overview
3. Techniques of schedule compression.
4. Activity Costs (Direct and indirect).
5. Methods and Schedule compression Impact to cost.
6. Procedures.
7. Examples.
8. Primavera Case Study.
10/9/2017Eng. Ahmed Said 3

INTRODUCTION
• Businesses owners rely on first-to-market product
strategies to gain competitive advantage and
increase profit margins. Within the construction
industry, this has created a growing need for
enhanced performance delivery systems that can
achieve successful project delivery in shorter time.
• Owners demand greater improvements in the
quality of project construction at lower costs and
within reduced schedules. The completion of
project’s time milestones is a crucial factor because
not meeting them usually involves significant
economic impacts to the owner while time savings
can lead to profit improvements.
• Schedule Acceleration Techniques Dr. Jesús M.

INTRODUCTION
• Project scheduling can play an important role in the
success of a construction project. This is especially true as
new project delivery methods such as design-build further
shorten already compressed work schedules.
• Agreed-upon project schedules allow the owner an
opportunity to efficiently plan its production operations
and therefore generate revenue, while the contractor can
efficiently plan its use of labor, equipment, and resources
to optimize the construction process.
• Therefore, it is not a surprise that many construction
disputes revolve around project scheduling and schedule
delays – time is money.
• https://www.interface-consulting.com/acceleration-experts/

Determining priorities
• Any Contractor has tow objectives (Targets):
1. Finishing on—or ahead of—schedule (contractor and the
owner agreed for this ?!).
2. Finishing on—or under—budget is another important
objective to the contractor and the owner also.
• Once you know the your objectives and your
budget flexibility, you can determine the best
actions to undertake to get you back on track or
gain a benefits.
• Achieving these two objectives is desirable—and
usually possible—you must rank them in order of
importance: one before the other.

What is schedule acceleration and compression?
• Schedule acceleration or compression is a very intense
time during the construction process when resources, such
as materials and labor, are consumed at a much faster pace
than anticipated.
• As the name implies, more work must be performed in the
same amount of time — or the same amount of work must
be performed in less time.
• On typical projects, it's a combination of both.
• As needs change during the acceleration process, the time
to respond becomes much shorter.
• Managers and supervisors who are trained to be proactive
must become reactive to meet these changing needs.
• Bob Mitchell | Apr 01, 2009

Why Accelerate a Project?
• There are many reasons, including the following :
Meet the contractually required time or recover delays. and avoid the contract liquidated damages clause
Best use of individual project team members’ expertise.
Save the company’ relationships and reputations in market and move to another projects may increase the company profile.
Generate a high experience in project selection, starting another job earlier making more profit.
Avoid claims, market changes and crises.
To gain contractual incentive payment related to completing a project before a specific date.
Most effective use of available funds.

Who is responsible?
• The project manager and management at one or more
of the previous reasons or at certain situation, take a
decision between next alternatives and more:
1. Optimize flexibility in contracting/procurement
options.
2. Use Optimal project/program scheduling options.
3. If it costs more do not shorten the duration anymore
and keep the cost to a minimum. (Primavera Real
Case Study)
4. If time is your target continue compressing the
schedule even though the cost will continue to rise.

Why Projects Take More or Less Time?
• Construction projects may take more or less time than
planned (usually more rather than less) for reasons that
may be within or beyond the contractor’s control.
• Reasons beyond the contractor’s control, such as:
• Force majeure,
• Differing site conditions,
• And change orders; draw time extensions from the owner in most
cases.
• These situations are not discussed in this slides. Instead,
the discussion is restricted to the ways the contractor can
influence the duration of the project.
• (construction projects scheduling and control 3rd edition, Saleh Mubarak)

Projects deadlines overview :
• 2- International commitment and a loss of money so
slippage not allowed.
• World Cup (Qatar 2022) or international exhibits or
conferences.
• 1- general public interest of or convenience to the.
• An example is a highway, a school, or a water treatment
plant and Riyadh Metro.
• Construction projects always have contractually finish
deadlines assigned by the owner for one or more of the
following reasons:

Projects deadlines overview :
• Finishing means missing the season and losing
profits/revenue.
• An example of such projects is a hotel or a shopping center for
a certain tourist or shopping season. (Holy City hotels at
Umm Al Qura Mecca)
• Another projects, not tied to a specific event or season, may have ‘‘normal’’
finish dates, which means the contractor can work at a ‘‘normal’’ pace.
Slipping a few days or weeks in this case may be acceptable to the owner
and may not cause serious consequences (construction projects scheduling and control 3rd edition,
Saleh Mubarak).

What are the techniques of schedule compression?
• There are several ways in which the work can be
accelerated, including, but not limited to, the following:
1. Working overtime or implementing a new shift.
2. Improving productivity/Improve processes :
• Provide incentives to workers or crews.
• Give the work as package related to time to workers or crews.
3. Providing additional labor or adding other resources (i.e.,
equipment).
4. Re-sequencing work activities.
5. Fast-track the project.
6. Use value engineering and constructability studies.

What are the techniques of schedule compression?
7. Change Management (Improve project management or supervision).
8. Use new technologies, special materials and/or equipment that help speed
up the work process.
9. Improve communications among parties, particularly during the submittal
process: Sometimes a structural subcontractor may have an inquiry about a
structural detail. The contract stipulates a chain of command requiring the
subcontractor to submit his request for information (RFI) to the general
contractor, who sends it to the architect, who in turn forwards it to the
structural engineer (construction projects scheduling and control 3rd edition, Saleh Mubarak) .
10. Prevent all scope change (Freezing of Project scope).
11. Eliminate waste and non-value adding activities (Lean
Design/construction).
12. Just-in-time delivery (no delay, no store and good use of funds).
13. Change Constructability method.
• Each of these acceleration efforts can be effective in some cases;
however, acceleration efforts can be expensive and do not guarantee
early or on-time completion of the work.

DIRECT AND INDIRECT COSTS
• From this web site https://web.nibs.org/ you can find more information.
• A contractor’s main expenses are as follows:
I. Direct costs
• Labor, particularly hourly workers, for whom a labor expense can be directly linked to a
particular work item.
• Materials, such as concrete, rebar, bricks, nails, paint and installed equipment, such as elevators,
air-conditioning units, and kitchen equipment.
• Equipment, mainly construction equipment (bulldozers, excavators, cranes, concrete pumps, etc.)
• Subcontractors (even though subcontractors’ charges comprise labor, materials, equipment,
overhead, and possibly sub-subcontractors, the general contractor treats these charges as a direct
cost)
• Other costs, such as government permits and fees, and fees for lawyers and consultants hired for
a specific task in a project.
• (construction projects scheduling and control 3rd edition, Saleh Mubarak) .

II. Indirect costs (UFC 3-740-05)
• GENERAL
• Overhead costs are those costs, which cannot be attributed to a single task of
construction work. Costs, which can be applied to a particular item of work should be
considered a direct cost to that item and are not to be included in overhead costs. The
overhead costs are customarily divided into two categories:
• Job office overhead (JOOH) also referred to as General Conditions or Field Office Overhead.
• General home office overhead commonly referred to as General and Administrative (G&A)
costs.
A. Project overhead (or job overhead), such as the following:
• Job overhead costs are those costs at the project site, which occur specifically as a result of
that particular project. Some examples of job overhead costs are:
1. Job supervision and office personnel.
2. Engineering and shop drawings/surveys.

3. Site security.
4. Temporary facilities, project office.
5. Temporary material storage.
6. Temporary utilities.
7. Preparatory work and laboratory testing.
8. Transportation vehicles.
9. Supplies and maintenance facilities.
10. Temporary protection and Occupational Safety and Health
Administration (OSHA) requirements.

6. (OSHA) requirements.
7. Telephone and communications.
8. Permits and licenses.
9. Insurance (project coverage).
10. Schedules & reports.
11. Quality control.
12. Cleanup.
13. Taxes.
14. Equipment costs not chargeable to a specific task.
15. Operation and maintenance of temporary job-site facilities.

• II. Indirect costs (UFC 3-740-05)
B. Mobilization and Preparatory Work
• The costs of mobilization and preparatory work, including the setup and removal of construction facilities
and equipment are part of overhead costs unless there is a specific bid item.
C. General overhead, such as the following:
1. Main office building, furniture, equipment.
2. Management and office staff, salary and expense.
3. Utilities, office equipment and vehicles.
4. General communications and travel.
5. Supplies.
6. Corporate vehicles.
7. General business insurance.
8. Taxes.
9. Main office services, such as lawyers and accountants (not working exclusively for a specific project)
10. Other main office expenses, such as advertising and charity contributions

• II. Indirect costs
D. Profit is defined as a return on investment. It is what provides the contractor with an incentive to perform the
work as efficiently as possible, but the preferred one is ‘‘return for taking risk,’’ thus profit amount (or
percentage) is usually proportional to the risk taken. A uniform profit rate should be avoided (UFC 3-740-05).
• Profit usually estimated by the contractor during bidding.
E. Contingency fees (an additional sum of money allocated for the unknown events that will most likely occur
during the life of the project; they are directly proportional to the risk taken in the project).
• For example, if you pay someone to set up concrete forms for a shear wall, the expense is direct.
• If you pay a security guard to look after the project, the expense is indirect.

• DURATION OF OVERHEAD ITEMS
• After the overhead items have been listed, a cost must be determined for each. Each item
should be evaluated separately.
• Some items such as erection of the project office may occur only once in the project.
• The cost engineer should utilize the developed job schedule in estimating duration
requirements.
• Costs reflective of each particular item during the scheduled period should then be applied.
The product of duration and unit cost is the overhead cost for the item.

Definitions Related to Schedule Compression
• Tn = normal time to complete an activity
• Tc = normal cost to complete an activity
• Cn = crash time to complete an activity, that is, the shortest possible time
it could be completed in.
• Cc = crash cost - the cost to complete the activity if it is performed in it’s
shortest possible time..
• The normal time is actually the shortest time required to perform the
activity under the minimum direct cost constraint.

How to Choose the Best Method for Project Acceleration
• Using accelerating methods that incur minimal cost (or
have the lowest cost-benefit ratio) generally makes sense.
Let us consider some of the different methods.
• Overtime:
• costs more per hour, might contribute to lower productivity. This fact
does not automatically disqualify overtime as a means for accelerating
projects. However, all the pros and cons should be considered before a
decision is made to use this method.
• Acquiring more workers and equipment:
• May lead to site congestion and less efficiency. In addition, it may
create a problem for the human resources and equipment departments:
what to do with excess resources after the peak need ends.

How to Choose the Best Method for Project Acceleration
• Hiring a second, and possibly a third, shift:
• May lead to more turnover time, result in more communication
problems, and require more careful management coordination.
• Extended work hours, because of the second and possibly the third
shifts, may require artificial lighting or special nighttime
arrangements (for example, services and security). In addition, it may
create a problem for the human resources and equipment
departments: what to do with excess resources after the peak need
ends.
• Acquiring special materials or more efficient equipment:
• Must be evaluated on its merits on a case-by-case basis. Such
acquisition almost always costs more, but the contractor must look at
the cost-benefit ratio and other related factors (for example, public
relations, customer satisfaction, and long-term impact).

Effect of Acceleration on Direct Costs
• In many cases, the relationship between the
direct cost and the duration for an activity is
approximately linear.
• A shorter activity duration usually costs more
• Both per unit time and in total.
• There is almost always a limit to how much the
duration can be compressed.
• The normal 8-hours-per-day, 6-days-per-week, the worker
works 48 hours/week, they will work 2 hours more every
day so 12 of which are overtime. If overtime rate is at 1.5
times the normal rate, the worker will receive 66 hours’
worth of pay for the 60 hours’ work. The additional pay
ratio is 66/48 x 100% = 137.5%.
• The increase in labor cost will be 37.5%.

Effect of Acceleration on Indirect Costs
• The indirect cost tends to increase if more time is
consumed for the project.
• The indirect cost is generally vary approximately
linearly with the time.

Effect of Acceleration on Cost

Effect of Acceleration on Total Cost
• When accelerating a project, many issues have to
be considered such as design and construction
delivery methods (fast-track?), frequency of
updating (schedule by the hour?), shift turn over,
equipment cost/maintenance, managing subs,
procurement/ materials management, permits,
government regulations (road restriction), cash-
flow, job site congestion, and safety and security,.
The scheduler may also review activities
duration, logic, and allocated resources.

The general procedures for crashing is:
1. Obtain estimates of regular and crash times and
costs for each activity.
2. Determine the lengths of all paths and path slack
times.
3. Determine which are the critical activities.
4. Crash critical activities, in order of increasing costs,
as long as crashing costs do not exceed benefits. In
some cases, it will be more economical to shorten
an activity that is on two (or more) of the critical
paths. This is true whenever the crashing cost of a
join activity is less than the sum of costs of crashing
one activity on each separate path.

Modified Siemens Algorithm
• The 8 step hand procedure presented below is a slight modification of the
method developed by Siemens. The key element of this procedure is the
cost slope and time available. The cost slope will be denoted by Cij for an
arbitrary activity (i – j).
1. Cost Slope (Cij) for an arbitrary activity (i – j) =
[Crash cost (Cd) - Normal cost (CD)]ij / [Normal duration (D) - Crash duration(d)]ij
2. Time Available (TAij) = [Normal duration (D ) - Crash duration(d)]ij
• An “effective” cost slope, ECij, is defined as the cost slope divided by the
number of inadequately shortened paths, Nij, which contain activity (i –j)
3. Effective Cost Slope (ECij) =
• Cost slope (Cij) / Number of inadequately shortened paths (Nij)
• The procedure described below chooses from among all available
activities to be shortened, the one with the lowest effective cost slope.

The general procedures for crashing is:
1- Project
Schedule/Network
2 - list all paths > the
desired (scheduled)
project duration
3 - List all activities
presented in at least
one of the listed paths
4 – Derivation for each
activity its cost slope
5 - For the longest
path(s) select the
activity with the
lowest effective cost
slope
6 – Cut/shorten the
selected activity as
much as possible,
which will shorten
path(s) next
7 - Stop if all paths
have been adequately
shortened
8 - If not Return to Step
5

Example 1
• The durations and direct costs for each activity
in the network of a small engineering project
under both normal and crash conditions are
given in below Table.
• Determine the optimum duration of the
contract assuming the indirect cost amounts to
$ 140/ day.
Duration Cost
Activity Depen. Normal Crash Normal Crash
A 13 11 6800 7000
B A 9 7 4700 5000
C A 15 12 4000 4600
D B 23 23 5000 5000
E B 5 4 1000 1100
F C 6 5 3000 3300
G E,C 20 15 6000 6300
H F 13 11 2500 2580
I D, G, H 12 10 3000 3150
36000 38030

Example 1

Example 1
A A A A
C B C B
E F D
G G H
I I I I
Duration Cost Iterations
Activity Depen. Normal Crash Normal Crash Cost Var. ∆ Time
Cost
Slope 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1 2 3 4 5
A 13 11 6800 7000 200 2 100
B A 9 7 4700 5000 300 2 150
C A 15 12 4000 4600 600 3 200
D B 23 23 5000 5000
E B 5 4 1000 1100 100 1 100
F C 6 5 3000 3300 300 1 300
G E,C 20 15 6000 6300 300 5 60
H F 13 11 2500 2580 80 2 40
I D, G, H 12 10 3000 3150 150 2 75
36000 38030 Reduction days 60 59 59 57
60
60 60 59 59 57
Cost incresed
Direct Cost
36000
Indirect Cost 140
Total Cost
44400
Project
Duaration/iterations
A A A A
C B C B
E F D
G G H
I I I I
Cost
Slope 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1 2 3 4 5
A 13 11 6800 7000 200 2 100
B A 9 7 4700 5000 300 2 150
C A 15 12 4000 4600 600 3 200
D B 23 23 5000 5000
E B 5 4 1000 1100 100 1 100
F C 6 5 3000 3300 300 1 300
G E,C 20 15 6000 6300 300 5 60 1 1 1
H F 13 11 2500 2580 80 2 40
I D, G, H 12 10 3000 3150 150 2 75
36000 38030 Reduction days 1 60 59 59 57
60 59 1 1
59 59 59 58 59 57
Cost incresed 60
Direct Cost
36000
36060
Indirect Cost 140
8260
Total Cost
44400
44320
Project
A A A A
C B C B
E F D
G G H
I I I I
Cost
Slope 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1 2 3 4 5
A 13 11 6800 7000 200 2 100
B A 9 7 4700 5000 300 2 150
C A 15 12 4000 4600 600 3 200
D B 23 23 5000 5000
E B 5 4 1000 1100 100 1 100
F C 6 5 3000 3300 300 1 300
G E,C 20 15 6000 6300 300 5 60 1 1 1
H F 13 11 2500 2580 80 2 40
I D, G, H 12 10 3000 3150 150 2 75 1 1 2 2 2 2
36000 38030 Reduction days 1 1 1 60 59 59 57
60 59 58 57 3 3 2 2
57 57 57 57 57 56 57 55
Cost incresed 60 75 75
Direct Cost
36000
36060
36135
36210
Indirect Cost 140
8260
8120
7980
Total Cost
44400
44320
44255
44190
Project
A A A A
C B C B
E F D
G G H
I I I I
Cost
Slope 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1 2 3 4 5
A 13 11 6800 7000 200 2 100 1 1 2 2 2 2
B A 9 7 4700 5000 300 2 150
C A 15 12 4000 4600 600 3 200
D B 23 23 5000 5000
E B 5 4 1000 1100 100 1 100
F C 6 5 3000 3300 300 1 300
G E,C 20 15 6000 6300 300 5 60 1 1 1
H F 13 11 2500 2580 80 2 40
I D, G, H 12 10 3000 3150 150 2 75 1 1 2 2 2 2
36000 38030 Reduction days 1 1 1 1 1 60 59 59 57
60 59 58 57 56 55 5 5 4 4
55 55 55 55 55 55 55 54 55 53
Cost incresed 60 75 75 100 100
Direct Cost
36000
36060
36135
36210
36310
36410Indirect Cost 140
8260
8120
7980
7840
7700
Total Cost
44400
44320
44255
44190
44150
44110
Project
A A A A
C B C B
E F D
G G H
I I I I
Cost
Slope 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1 2 3 4 5
A 13 11 6800 7000 200 2 100 1 1 2 2 2 2
B A 9 7 4700 5000 300 2 150
C A 15 12 4000 4600 600 3 200 1 1 1
D B 23 23 5000 5000
E B 5 4 1000 1100 100 1 100
F C 6 5 3000 3300 300 1 300
G E,C 20 15 6000 6300 300 5 60 1 1 1
H F 13 11 2500 2580 80 2 40
I D, G, H 12 10 3000 3150 150 2 75 1 1 2 2 2 2
36000 38030 Reduction days 1 1 1 1 1 1 60 59 59 57
60 59 58 57 56 55 54 6 5 5 4
54 54 54 54 54 54 54 54 54 54 53
Cost incresed 60 75 75 100 100 200
Direct Cost
36000
36060
36135
36210
36310
36410
36610
Indirect Cost 140
8260
8120
7980
7840
7700
7560Total Cost
44400
44320
44255
44190
44150
44110
44170
Project
A A A A
C B C B
E F D
G G H
I I I I
Cost
Slope 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1 2 3 4 5
A 13 11 6800 7000 200 2 100 1 1 2 2 2 2
B A 9 7 4700 5000 300 2 150
C A 15 12 4000 4600 600 3 200 1 1 2 2
D B 23 23 5000 5000
E B 5 4 1000 1100 100 1 100
F C 6 5 3000 3300 300 1 300
G E,C 20 15 6000 6300 300 5 60 1 1 1
H F 13 11 2500 2580 80 2 40
I D, G, H 12 10 3000 3150 150 2 75 1 1 2 2 2 2
36000 38030 Reduction days 1 1 1 1 1 1 1 60 59 59 57
60 59 58 57 56 55 54 53 7 5 6 4
54 54 54 54 54 54 54 54 53 54 53 53
Cost incresed 60 75 75 100 100 200 200
Direct Cost
36000
36060
36135
36210
36310
36410
36610
36810
Indirect Cost 140
8260
8120
7980
7840
7700
7560
7420
Total Cost
44400
44320
44255
44190
44150
44110
44170
44230
Project
A A A A
C B C B
E F D
G G H
I I I I
Cost
Slope 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1 2 3 4 5
A 13 11 6800 7000 200 2 100 1 1 2 2 2 2
B A 9 7 4700 5000 300 2 150
C A 15 12 4000 4600 600 3 200 1 1 2 2
D B 23 23 5000 5000
E B 5 4 1000 1100 100 1 100
F C 6 5 3000 3300 300 1 300
G E,C 20 15 6000 6300 300 5 60 1 1 2 2
H F 13 11 2500 2580 80 2 40
I D, G, H 12 10 3000 3150 150 2 75 1 1 2 2 2 2
36000 38030 Reduction days 1 1 1 1 1 1 1 1 60 59 59 57
60 59 58 57 56 55 54 53 54 8 6 6 4
53 53 53 53 53 53 53 53 53 52 53 53 53
Cost incresed 60 75 75 100 100 200 200 60
Direct Cost
36000
36060
36135
36210
36310
36410
36610
36810
36870
Indirect Cost 140
8260
8120
7980
7840
7700
7560
7420
7560
Total Cost
44400
44320
44255
44190
44150
44110
44170
44230
44430
Project
A A A A
C B C B
E F D
G G H
I I I I
Cost
Slope 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1 2 3 4 5
A 13 11 6800 7000 200 2 100 1 1 2 2 2 2
B A 9 7 4700 5000 300 2 150 1 1 1
C A 15 12 4000 4600 600 3 200 1 1 2 2
D B 23 23 5000 5000
E B 5 4 1000 1100 100 1 100
F C 6 5 3000 3300 300 1 300
G E,C 20 15 6000 6300 300 5 60 1 1 2 2
H F 13 11 2500 2580 80 2 40
I D, G, H 12 10 3000 3150 150 2 75 1 1 2 2 2 2
36000 38030 Reduction days 1 1 1 1 1 1 1 1 1 60 59 59 57
60 59 58 57 56 55 54 53 54 53 8 7 6 5
53 53 53 53 53 53 53 53 53 53 52 52 53 52
Cost incresed 60 75 75 100 100 200 200 60 150
Direct Cost
36000
36060
36135
36210
36310
36410
36610
36810
36870
37020
Indirect Cost 140
8260
8120
7980
7840
7700
7560
7420
7560
7420
Total Cost
44400
44320
44255
44190
44150
44110
44170
44230
44430
44440
Project
A A A A
C B C B
E F D
G G H
I I I I
Cost
Slope 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1 2 3 4 5
A 13 11 6800 7000 200 2 100 1 1 2 2 2 2
B A 9 7 4700 5000 300 2 150 1 1 2 2
C A 15 12 4000 4600 600 3 200 1 1 2 2
D B 23 23 5000 5000
E B 5 4 1000 1100 100 1 100
F C 6 5 3000 3300 300 1 300
G E,C 20 15 6000 6300 300 5 60 1 1 2 2
H F 13 11 2500 2580 80 2 40
I D, G, H 12 10 3000 3150 150 2 75 1 1 2 2 2 2
36000 38030 Reduction days 1 1 1 1 1 1 1 1 1 1 60 59 59 57
60 59 58 57 56 55 54 53 54 53 52 8 8 6 6
53 53 53 53 53 53 53 53 53 53 53 52 51 53 51
Cost incresed 60 75 75 100 100 200 200 60 150 150
Direct Cost
36000
36060
36135
36210
36310
36410
36610
36810
36870
37020
37170
Indirect Cost 140
8260
8120
7980
7840
7700
7560
7420
7560
7420
7280
Total Cost
44400
44320
44255
44190
44150
44110
44170
44230
44430
44440
44450
Project
A A A A
C B C B
E F D
G G H
I I I I
Cost
Slope 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1 2 3 4 5
A 13 11 6800 7000 200 2 100 1 1 2 2 2 2
B A 9 7 4700 5000 300 2 150 1 1 2 2
C A 15 12 4000 4600 600 3 200 1 1 1 3 3
D B 23 23 5000 5000
E B 5 4 1000 1100 100 1 100
F C 6 5 3000 3300 300 1 300
G E,C 20 15 6000 6300 300 5 60 1 1 2 2
H F 13 11 2500 2580 80 2 40 1 1
I D, G, H 12 10 3000 3150 150 2 75 1 1 2 2 2 2
36000 38030 Reduction days 1 1 1 1 1 1 1 1 1 1 1 1 60 59 59 57
60 59 58 57 56 55 54 53 52 51 50 49 48 9 8 8 6
51 51 51 51 51 51 51 51 51 51 51 51 51 51 51 51 51
Cost incresed 60 75 75 100 100 200 200 60 150 150 40 200
Direct Cost
36000
36060
36135
36210
36310
36410
36610
36810
36870
37020
37170
37210
37410
Indirect Cost 140
8260
8120
7980
7840
7700
7560
7420
7280
7140
7000
6860
6720
Total Cost
44400
44320
44255
44190
44150
44110
44170
44230
44150
44160
44170
44070
44130
Project
A A A A
C B C B
E F D
G G H
I I I I
Cost
Slope 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1 2 3 4 5
A 13 11 6800 7000 200 2 100 1 1 2 2 2 2
B A 9 7 4700 5000 300 2 150 1 1 2 2
C A 15 12 4000 4600 600 3 200 1 1 1 3 3
D B 23 23 5000 5000
E B 5 4 1000 1100 100 1 100
F C 6 5 3000 3300 300 1 300
G E,C 20 15 6000 6300 300 5 60 1 1 2 2
H F 13 11 2500 2580 80 2 40 1 1
I D, G, H 12 10 3000 3150 150 2 75 1 1 2 2 2 2
36000 38030 Reduction days 1 1 1 1 1 1 1 1 1 60 59 59 57
60 59 58 57 56 55 54 53 52 51 9 8 8 6
51 51 51 51 51 51 51 51 51 51 51 51 51 51
Cost incresed 60 75 75 100 100 200 260 150 390
Direct Cost
36000
36060
36135
36210
36310
36410
36610
36870
37020
37410
Indirect Cost 140
8260
8120
7980
7840
7700
7560
7420
7280
7140
Total Cost
44400
44320
44255
44190
44150
44110
44170
44290
44300
44550
Project

Example 1
35000
35500
36000
36500
37000
37500
38000
59 58 57 56 55 54 53 52 51
Direct Cost
6400
6600
6800
7000
7200
7400
7600
7800
8000
8200
8400
59 58 57 56 55 54 53 52 51
Indirect Cost

Example 1
43800
43900
44000
44100
44200
44300
44400
44500
44600
59 58 57 56 55 54 53 52 51
Total Cost

Example 2
• Calculate the normal, least-cost, and crash
durations for the following project.
• Calculate the cost associated with each
duration. Indirect (overhead) costs are $120 per
day.
Duration Cost
Activity Depen. Normal Crash Normal Crash
A 5 4 500 600
B A 7 5 350 500
C A 8 5 800 920
D A 11 7 1200 1400
E B,C 6 4 600 700
F C 4 4 500 500
G D,F 7 5 700 1000
H E,F 6 5 300 420
4950 6040

Example 2
A
50
550
C
135
1385
B
125
1376
D
165
18117
F
1713
18414
G
2417
25718
H
2519
25619
E
1913
19613
Finish
2525
25025

Example 2
A A A A A
B C C C D
E E F F
H H H G G
Cost
Slope 1 2 3 4 5 6 7 1 2 3 4 5
A 5 4 500 600 100 1 100 1 1 1 1 1 1
B A 7 5 350 500 150 2 75 1 1 2
C A 8 5 800 920 120 3 40 1 1 1 3 3 3
D A 11 7 1200 1400 200 4 50 1 1 2
E B,C 6 4 600 700 100 2 50 1 1 2 2
F C 4 4 500 500
G D,F 7 5 700 1000 300 2 150 1 1 2 2
H E,F 6 5 300 420 120 1 120 1 1 1 1
4950 6040 Reduction days 1 1 1 1 1 1 1 24 25 23 24 23
25 24 23 22 21 20 19 18 6 7 5 6 5
18 18 18 18 18 18 18 18 18 18 18 18 18
Cost incresed 40 50 100 140 165 225 270
Direct Cost 4950
4990
5040
5140
5280
5445
5670
5940
Indirect Cost 120
2880
2760
2640
2520
2400
2280
2160
Total Cost 7950
7870
7800
7780
7800
7845
7950
8100
Project Duaration/iterations

Project Study With Primavera
• Project is medical city include staff housing.
• Staff housing is 12.56% from the total of project.
• Planned parallel using line of balance technique.
• During 3month lookahead preparation
information is masons will released from another
site at a certain date.
• This cause a delay by 17day (not acceptable and
cause delay in 3ML targets.
• Required to recover this delay.

• In our case we will study one group of buildings and the result will apply
to all groups.
This what will recovered
by crashing critical path
=21 Calendar Dates

• R402,595.83Site Overhead 3month average (monthly)=
R15,484.45Site Overhead 3month average (daily)=
R154,844.5021 Days costs
R1935.56Staff housing share of cost (it according work progress weight)=12.56%
All this information from project plan and finance dept. with
the project manager as a total not like this table.
Wait :
Still Remaining
• Site consumptions Fuel and transportations …...
• General overhead.

• Labor Cost
• Example: Crew is 2 skilled + 1 non-skille
•
•
•
3000 2500 2000 1500 1000 ‫ي‬ ‫اﻷساس‬
(‫تضاف‬ ‫)لم‬ ‫ة‬‫العمال‬ ‫وم‬‫رس‬
Iqama 650 650 650 650 650 650 ‫ة‬‫اﻹقام‬ ‫مصروفات‬
Labor License 2500 2500 2500 2500 2500 2500 ‫العمل‬ ‫كارت‬
Midical Insurance 1000 1000 1000 1000 1000 1000 ‫الطبي‬ ‫تأمين‬
Visa For 2 years 2300 1150 1150 1150 1150 1150 ‫يرة‬‫التأش‬ ‫تحمل‬ ‫نسبة‬
Ticket For 2 years 3000 1500 1500 1500 1500 1500 ‫فر‬‫الس‬ ‫ذاكر‬‫ت‬
Housing & Trans. 3000 3000 3000 3000 3000 3000 ‫اﻻت‬ ‫انتق‬ ‫و‬ ‫كن‬‫س‬
Vacation For 2 years 2100 1750 1400 1050 700 ‫ازة‬‫اﻷج‬
Indemnity 1500 1250 1000 750 500 ‫ة‬‫الخدم‬ ‫نهاية‬ ‫حصة‬
OH 10% 1245 1245 1245 1245 1245 1245 ‫ة‬‫اﻹداري‬ ‫اريف‬‫المص‬ ‫من‬ ‫نسبة‬
Total Annual fees ‫اجمالي‬ 13695 14645.0 14045.0 13445.0 12845.0 12245.0
Total Monthly fees ‫اجمالي‬ 1220.4 1170.4 1120.4 1070.4 1020.4
Total Monthly 4220.4 3670.4 3120.4 2570.4 2020.4
Total Daily 162.3 141.2 120.0 98.9 77.7
Total Daily 160 140 120 100 80
Skilled Non-Skilled

• Crash Duration:
• For this item we have 144 Mhr for electrician (Driven resource).
• We need compressing this activity, so we need to accomplish 144 Mhr in a short
time (shortening from original duration 6 days as possible)
• Using this formula
•
. ×( × ) ×( × . )

• Primavera concept:

• Crash Duration and Cost
Normal
Duration
Normal Cost
Crash
Duration Crash Cost Revenue
Activity ID Activity Name
Designation
Predecessors
Original
Duration
nonSkilledMHr
nonSkilled
SkilledMHr
Skilled
CostSR/day
CostSR/hr
CostSR
CrashDuration
Var
nonSkilledMHr
nonSkilled
SkilledMHr
Skilled
CostSR/day
CostSR/hr
CostSR
TotalFloat
BudgetedTotal
Price
FAM1100 RC Works for Columns & Walls A 0 12 96 1 192 2 380.00 47.50 4,560.00 12 0 1 2 380.00 38.00 4,560.00 0 35,918.75
FAM1110 RC Works For Ground Floor Slab B A 16 128 1 256 2 380.00 47.50 6,080.00 16 0 1 2 380.00 38.00 6,080.00 0 183,850.70
FAM1130 Under slab drainage Piping For Next Floor C B 3 24 1 48 2 380.00 47.50 1,140.00 3 0 1 2 380.00 38.00 1,140.00 0 6,399.95
FAM1160 Masonary Works For Internal Walls D C+17,B 18 144 1 288 2 380.00 47.50 6,840.00 15.32 16 -2 1 2 522.50 52.25 8,360.00 0 54,472.20
FAM1230 Installation of UPVC Pipes Class 4 E D 7 112 2 168 3 620.00 77.50 4,340.00 5.96 7 0 2 3 620.00 62.00 4,340.00 13 2,128.18
FAM1220 Internal Drainage Piping F D 5 40 1 120 3 520.00 65.00 2,600.00 4.26 5 0 1 3 520.00 52.00 2,600.00 13 19,200.61
FAM1210 Data & Telephone System AS Conduits Installation G D 10 160 2 240 3 620.00 77.50 6,200.00 8.51 10 0 2 3 620.00 62.00 6,200.00 1 641.21
FAM1200 Fire Alarm System US Conduits & Boxes Installation H D 8 128 2 256 4 760.00 95.00 6,080.00 6.81 8 0 2 4 760.00 76.00 6,080.00 1 1,640.77
FAM1190 Power Sockets System AS Conduits Installation I D 6 96 2 144 3 620.00 77.50 3,720.00 3.83 4 -2 2 4 1,045.00 104.50 4,180.00 0 2,768.26
FAM1240 Internal Cold & Hot water supply Piping J D+4 8 128 2 192 3 620.00 77.50 4,960.00 6.81 8 0 2 3 620.00 62.00 4,960.00 16 28,413.22
FAM1260 Lighting System Wall Conduits and Boxes Installation K I 8 128 2 192 3 620.00 77.50 4,960.00 6.81 8 0 2 3 620.00 62.00 4,960.00 2 7,884.15
FAM1250 Power Sockets System Wall Conduits and Boxes Installation L I 6 96 2 144 3 620.00 77.50 3,720.00 3.83 4 -2 2 4 1,045.00 104.50 4,180.00 0 2,768.26
FAM1270 Data & Telephone System Wall Conduits and Boxes Installation M G,D 8 128 2 192 3 620.00 77.50 4,960.00 6.81 8 0 2 3 620.00 62.00 4,960.00 1 641.21
FAM1300 Power Sockets System Wall Boxes Final Installation N I,L 7 112 2 168 3 620.00 77.50 4,340.00 5.96 7 0 2 3 620.00 62.00 4,340.00 0 2,768.26
FAM1310 Lighting System Wall Final Boxes Installation O K 8 128 2 192 3 620.00 77.50 4,960.00 6.81 8 0 2 3 620.00 62.00 4,960.00 2 7,884.15
FAM1320 Fire Alarm System Wall Conduits and Boxes Installation P H,N,D 8 128 2 256 4 760.00 95.00 6,080.00 5.45 6 -2 3 5 1,375.00 137.50 8,250.00 0 1,640.77
FAM1340 Data & Telephone System Wall Final Boxes Installation Q M+5,O 15 240 2 360 3 620.00 77.50 9,300.00 12.77 15 0 2 3 620.00 62.00 9,300.00 1 641.21
FAM1360 Call System US Conduits & Boxes Installation R P,D 8 64 1 128 2 380.00 47.50 3,040.00 6.81 8 0 1 2 380.00 38.00 3,040.00 4 530.19
FAM1350 Intercom System US Conduits & Boxes Installation S R 8 128 2 192 3 620.00 77.50 4,960.00 6.81 8 0 2 3 620.00 62.00 4,960.00 4 663.33
FAM1370 Fire Alarm System Wall Final Boxes Installation T D,P+4,H 13 208 2 416 4 760.00 95.00 9,880.00 8.85 9 -4 3 5 1,375.00 137.50 12,375.00 0 1,640.77
102,720.00 109,825.00 362,496.15

• Our Case Study
Duration Cost
Activity Activity Normal Crash Normal Crash
RC Works for Columns & Walls A 12 12 4560 4560
RC Works For Ground Floor Slab B 16 16 6080 6080
Under slab drainage Piping For Next Floor C 3 3 1140 1140
Masonary Works For Internal Walls D 18 16 6840 8360
Installation of UPVC Pipes Class 4 E 7 7 4340 4340
Internal Drainage Piping F 5 5 2600 2600
Data & Telephone System AS Conduits Installation G 10 10 6200 6200
Fire Alarm System US Conduits & Boxes Installation H 8 8 6080 6080
Power Sockets System AS Conduits Installation I 6 4 3720 4180
Internal Cold & Hot water supply Piping J 8 8 4960 4960
Lighting System Wall Conduits and Boxes Installation K 8 8 4960 4960
Power Sockets System Wall Conduits and Boxes Installation L 6 4 3720 4180
Data & Telephone System Wall Conduits and Boxes Installation M 8 8 4960 4960
Power Sockets System Wall Boxes Final Installation N 7 7 4340 4340
Lighting System Wall Final Boxes Installation O 8 8 4960 4960
Fire Alarm System Wall Conduits and Boxes Installation P 8 6 6080 8250
Data & Telephone System Wall Final Boxes Installation Q 15 15 9300 9300
Call System US Conduits & Boxes Installation R 8 8 3040 3040
Intercom System US Conduits & Boxes Installation S 8 8 4960 4960
Fire Alarm System Wall Final Boxes Installation T 13 9 9880 12375
102720 109825

• After 1st iterations:
D
I
L
P
R
T
Activity Activity Normal Crash Normal Crash Cost Var. ∆ Time
Cost
Slope 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5
RC Works for Columns & Walls A 12 12 4560 4560
RC Works For Ground Floor Slab B 16 16 6080 6080
Under slab drainage Piping For Next Floor C 3 3 1140 1140
Masonary Works For Internal Walls D 18 16 6840 8360 1520 2 760 1 1 2
Installation of UPVC Pipes Class 4 E 7 7 4340 4340
Internal Drainage Piping F 5 5 2600 2600
Data & Telephone System AS Conduits Installation G 10 10 6200 6200
Fire Alarm System US Conduits & Boxes Installation H 8 8 6080 6080
Power Sockets System AS Conduits Installation I 6 4 3720 4180 460 2 230 1 1
Internal Cold & Hot water supply Piping J 8 8 4960 4960
Lighting System Wall Conduits and Boxes Installation K 8 8 4960 4960
Power Sockets System Wall Conduits and Boxes Installation L 6 4 3720 4180 460 2 230
Data & Telephone System Wall Conduits and Boxes Installation M 8 8 4960 4960
Power Sockets System Wall Boxes Final Installation N 7 7 4340 4340
Lighting System Wall Final Boxes Installation O 8 8 4960 4960
Fire Alarm System Wall Conduits and Boxes Installation P 8 6 6080 8250 2170 2 1085
Data & Telephone System Wall Final Boxes Installation Q 15 15 9300 9300
Call System US Conduits & Boxes Installation R 8 8 3040 3040
Intercom System US Conduits & Boxes Installation S 8 8 4960 4960
Fire Alarm System Wall Final Boxes Installation T 13 9 9880 12375 2495 4 623.75 1 1 1 1 4
102720 109825 Reduction days 1 1 1 1 1 1 1 107
107 106 105 104 103 102 101 100 7
100 100 100 100 100 100 100 100 100
760 760 623.75 623.75 623.75 623.75 230
102720
103,480.00
104,240.00
104,863.75
105,487.50
106,111.25
106,735.00
106,965.00
1935.56
205,169.03
203,233.47
201,297.92
199,362.36
197,426.80
195,491.24
193,555.69
309825
308,649.03
307,473.47
306,161.67
304,849.86
303,538.05
302,226.24
300,520.69
Project Duaration/iterations
Cost incresed
Direct Cost
Indirect Cost
Total Cost

• After 1st iterations:

Impact of Compressing
Eng. Ahmed Said 10/9/2017 53
101000
102000
103000
104000
105000
106000
107000
108000
106 105 104 103 102 101 100
Direct Cost
186000
188000
190000
192000
194000
196000
198000
200000
202000
204000
206000
208000
106 105 104 103 102 101 100
Indirect Cost

Final Result is RECOVERY SCHEDULES
• In real-life projects, schedules may slip.
• This situation may concern the owner, especially if the project deadline is critical.
• The owner may demand that the contractor adjust the work plan to enable him or her to finish on
schedule.
• The owner must be convinced that the contractor can feasibly do so, or the owner may terminate
the contractor and hire another contractor to ensure a timely finish.
• When the contractor adjusts the schedule, the result is a recovery schedule.
• It can be defined as a schedule prepared during construction, after the project has fallen behind
(either the interim target has not been met or serious signs of failure to meet the deadline can be
seen), with adjustments by the contractor that expedite the remainder of the project and ensure a
timely finish.
• The recovery schedule may incorporate one or more of the techniques mentioned previously.
• Saleh Mubarak

References
• Modern Construction Management , FRANK HARRIS AND RONALD NCCAFFER
• www.google.com
• Construction projects scheduling and control 3rd edition, Saleh Mubarak
• UFC 03-740-05 HANDBOOK: CONSTRUCTION COST ESTIMATING.

‫علي‬ ‫التواصل‬ ‫يرجى‬:
‫صفحة‬
‫أو‬
‫واﻻستفسار‬ ‫اﻻسئلة‬‫ات‬

Time cost trade off with primavera (real case)

Time cost trade off with primavera (real case)

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