delay analysis class

8/13/2019 Delay Analysis Class

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Dr. Khalid Al-Gahtani, A specialized short course, King SaudUniversity 1

Delay Analysis

Techniques


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Dr. Khalid Al-Gahtani, A specialized short course, King Saud University 2March 2007

Contractor Delay:

In construction claims, a Delay is the

time during which some part of the

construction projects has been extendedor not performed due to an unanticipatedcircumstance.


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Parties Responsible for Delay

Contractor

Owner

Subcontractors Suppliers

Labor unions

Utility companies Nature


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Most common causes

Differing site conditions

Change in requirements or design

Inclement weather Unavailability of labor, material, or equipment

Defective plans or specifications, or

Owner caused delay: permits, owner-supplied, equipment, materials, ..etc.


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Construction Delay Types:

Excusable Delay

Compensable Delay (EC), time+$

Non-compensable Delay (EN) time

Nonexcusable Delay (NE)


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Critical and Noncritical Delays

Delays that result in extended projectcompletion are known as critical delays,

and

Delays that do not extend the projectcompletion date are called noncritical

delays.


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Critical and Noncritical Delays

a contractor will not be entitled to a timeextension for an excusable delay unless

the delay extends the overall projectcompletion.

an owner-caused delay need not delay theoverall contract performance time for a

contractor to recover its costs of delay. The delay need only affect the contractor's

cost of performance.


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Types of Schedules In Court

Network schedule.

Bar charts :

less effective than network schedules formeasuring delays.

High visibility of bar charts

Fragnet ScheduleIs a small part of a larger network diagram.


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Schedule must be

Reliable

Reflect the Intended Plan

Approved

Free from Mistakes

Free from Manipulations.


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Ways to prove Schedule

Reliability Show the unaffected part of plannedschedule matched the actual progress.

Showing how past similar projects werecompleted as originally schedule.

Showing the original sequences orduration match industry standard.

A schedule may also be found to be notreliable if the logic dose not considerpractical field restraints that control theconstruction sequence.


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Schedule Manipulations

Sometimes difficult to discover.

Only an expert scheduler can discover

these changes.

Hard to convince a judge or jury.

Do computers lie?


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Schedules Mistakes

Dangling Activity (Open end activities)

Fail to tie start of activities with submissionshop drawing, approval, fabrication, andmaterial delivery.

Contractors fail to recognize and scheduleother trade work,

Not providing sufficient mechanical details ina multiple activities.


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Schedule Manipulations

Reduced or Increased Activity duration.

Manipulated in activities constraints.

Manipulation of the activity status orhistory.

Change schedule sequencing.

Schedule the activity based on late start.


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Concurrent Delay

Delays that occur in parallel path activitiesin the same time period are classified as

concurrent delays. The concurrent delays may be:

all on critical paths,

all on noncritical paths, ordistributed between critical paths and

noncritical paths.


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Activity A

Activity B

Activity CActivity D

Activity E

Activity F

Concurrent Delay


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Concurrent Delay

Activity A EC Delay

Activity B

Activity CActivity D NE Delay

Activity E

Activity F

Delay


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Constructive Acceleration

Activity A

Activity B

Activity CActivity D

Activity E

Activity FOriginal TF

EC

CA


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Concurrent Delay

Difficulties posed by Concurrent Delay:

Changing of Critical Path as result of

consumption of Total Float.Defining the concurrency period time.

Defining the responsibilities of Concurrent

Delay.


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Concurrent Delay

Concurrent

DelayRemedy

(For Cri tical Activi ties)

Any delayconcurrent with

EN delayTime extension (EN)

ConcurrentEC/NE delay

Easy-rule Fair-ruleTime extension

(EN)Apportionment


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Pacing Delay*

Pacing Delay Definition:

Deceleration of the project work, by one of

the parties to the contract, due to a delayto the end date of the project caused bythe other party, so as to maintain steady

progress with the revised overall projectschedule. *

* Zack, 2000


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Acceleration in Delay Claims

which activity should be accelerated first:

The activity which has owner delayed

events, orThe activity which has the contractor

delayed events, or

The activity with the most cost savings.


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Owner Acceleration (OA).

Contractor Acceleration (CA).

Schedule Acceleration (SA).

Type Acceleration in Delay

Claims


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Delay Analysis Techniques

Global impact

technique, As-Built technique,

Adjusted as-built CPM

technique, As-Planned technique,

Impacted As-PlannedTechnique

The most popularly utilized delay analysistechniques are:

Time impact technique,

But-for technique, Window (Snapshot)

technique,

Isolated Delay Type(IDT), and

Window (But-For)technique .


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Main issues of these techniques.

Distinguish between delay types:

Non-excusable Delay (NE)

Excusable Compensable Delay (EC), and

Excusable Non-compensable Delay (EN)

Consider changing of critical path

Solve Concurrent Delay issues. Failure to address Pacing Delay.


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Global impact technique

Activity Delay Type DelayH NE 7

E NE 2

I NE 7

J NE 2

C NE 2

B EC 6

L EC 6

J EC 3

J EN 3

M EN 5

Total Delay Days 43


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As-Planned Techniques (Contractor)


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As-Planned Techniques (Owner)


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As-Built technique


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As-Built technique


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Adjusted as-built CPM Technique


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But-for technique (Contractor)


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But-for technique (Owner)


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Time impact technique (Activity I)


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Time impact technique (Activity I)

Window Snapshot technique


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Window Snapshot technique(Before)

Window Snapshot technique


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Window Snapshot technique(After)


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Isolated Delay Type (IDT)Technique (Contractor point of view)


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Isolated Delay Type (IDT)Technique (Owner point of view)

Wi d A l i (B t f


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Window Analysis (But forContractor)


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Window Analysis (But for Owner)


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Weaknesses of Current Delay

Analysis Techniques. Changing of activity criticalities during the

project progress,

Concurrent delay, Pacing Delay and unfair treatment of

Noncritical activities,

Difference between project and analysisschedule.

delay analysis class

Documents