سلسلة محاضرات إدارة المشاريع المقدمة من مؤسسة علماء مصر http://www.egyptscholars.org/pm

1. Project Management
Six Session
Egypt Scholars
Presented by
Mohamed Khalifa Hassan
Jan 2014
© Mohamed Khalifa, 2014 All Rights Reserved 1

2. © Mohamed Khalifa, 2010 All Rights Reserved 2
7. Scheduling

3. 7.1 Scheduling techniques
7.3 Critical path method
7.3 Logical schedule alternatives
© Mohamed Khalifa, 2010 All Rights Reserved 3
7. Scheduling

4. © Mohamed Khalifa, 2010 All Rights Reserved 4
7.1 Scheduling techniques
Activity sequencing is a planning process that involve
identifying and documenting interactivity dependencies
among project activities for the purpose of creating the
project schedule.
7.1.1 Activity sequencing

5. © Mohamed Khalifa, 2010 All Rights Reserved 5
7.1 Scheduling techniques
Dependency
Relationships
Description Example
Finish-to-start (FS) The predecessor activity must finish before the
successor activity can start.
The foundation for the house must be
finished (Activity A) before the framing
can start (Activity B)
Finish-to-Finish (FF) The predecessor activity must finished before
the successor activity can finish.
Construction must be finished (Activity A)
before the building inspection can be
finished (Activity B)
Start-to-Start (SS) The predecessor activity must start before the
successor activity can start. Can be expressed
as, "Activity A Must start before Activity B can
finish”
The building design must start (Activity A)
before the electrical layout design can
start (Activity B)
Start-to-Finish (SF) The predecessor activity must start before the
successor activity can finish. Activity A must
start before Activity B can finish
The electrical inspections must
start(Activity A) before you can finish dry
walling (Activity B)
Activity B
Successor
Activity A
Predecessor

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7.1 Scheduling techniques

7. © Mohamed Khalifa, 2010 All Rights Reserved 7
7.1 Scheduling techniques
Dependency determination:
Establishes dependencies among the activities, creating logical
sequences.
Dependency Description Example
Mandatory Hard Logic ; Dictated Work .The dependency is
inherent to the work itself. Activity must be
done in specific sequence
Books can’t be bound before they’re
printed
Discretionary Soft logic ; Preferred logic ; Best practice ;
preferential logic . Dependencies defined by the
project management team at their discretion
The sponsor would like to see the
book’s cover design as soon as
possible, so the team may decide to
have the cover artwork done before
the inside illustrations.
External Dependencies contingent on input
from outside the project activities
The books can’t be printed
until the shipment of paper
arrives

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7.2 Critical path method
• You created a project network diagram and acquired activity duration
estimates to help you develop your overall project schedule.
• Now you can establish the start and finish times for each of the activities
in your project and determine the duration of the entire project.
• You need to identify the critical path.

9. • Standard Diagram Notations
• ES : Early start . The earliest time an activity can start.
• EF : Early finish. The earliest time an activity can finish. The EF
for the first activity is same as its duration.
• LF Late finish. The latest time an activity can finish. The LF for
the last activity is the same as its EF time.
• LS late start. The latest time an activity can start. The LS for
last activity = EF-DU. LS for any predecessor activity = LF-DU
• DU Duration. The number of work periods required for
completion of an activity.
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Critical path:-
The Critical path is the network path that has the longest total duration. Activities on the
critical path cannot be delayed or the whole project will be delayed unless subsequent
activities are shortened.
© Mohamed Khalifa, 2010 All Rights
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7.2 Critical path method

10. • The Critical Path calculation:
– Calculated by doing forward pass to calculate ES & EF for each activity and then backward pass to
calculate the LS and LF for each activity.
– The path with longest total duration and no scheduling flexibility is the critical path (ES=LS &
EF=LF) & Float = 0
• Float :
– Float is the amount of time an activity can be delayed from its ES without delaying the project finish
date . In arrow diagramming method networks, float is called slack.
Total Float = Late Start (LS) – Early Start (ES) OR Late Finish (LF) – Early Finish (EF).
• Free Float :
– The amount of time an activity can be delayed without delaying the ES of any activity that
immediately follows it is known as free float. Free float is not shared among activities
– Free Float = ES of successor activity – (EF of the last activity + Lag).
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Free Float
Total Float
(Float) (Slack)Total Float
(Float)
(Slack) © Mohamed Khalifa, 2010 All Rights
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7.2 Critical path method

11. 11
Lag
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7.2 Critical path method

12. Workshop
(20 Min)
12© Mohamed Khalifa, 2010 All Rights Reserved

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7.3 Logical schedule alternative
7.3.1 Develop Schedule

14. Schedule network analysis:
– Produce the project schedule through a mix of analysis
– Schedule network analysis is a technique used to calculate the theoretical early and late start
and finish dates for all project activities. This also generates float or slack.
– Schedule network analysis may be achieved using one of four methods:
Critical Path Method (CPM) ; Critical Chain Method ;What-if Scenario and Resource Leveling
Critical path method (CPM)
– Analysis that calculates early and late start and finish dates for all activities in the
project.
Critical Chain Method:
– Alters the project schedule to accommodate limits on resources. Involves adding buffer
activities to keep focus on activity durations.
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7.3 Logical schedule alternative

15. Resource leveling:
– Assist in making scheduling decisions when there are resource management concerns.
What-if scenario analysis :
– Analysis that involves creating a scenario, (“What if X happened?”), and then
calculating various possible project durations.
– Simulation involves calculating multiple project duration with different set of
activity assumptions (Mont Carlo Simulation)
Adjusting lead and lags:
– Leads and lags may need to be adjusted to accommodate other scheduling elements.
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7.3 Logical schedule alternative

16. Schedule Compression:-
– Schedule compression is the shortening of the project schedule without
affecting the project scope.
– Compression may be achieved one of two ways:
1 – Fast tracking
2 - Crashing
1 - Fast Tracking :
• Fast tracking is the process of compressing total project duration by
performing some activities concurrently that were originally scheduled
sequentially.
• Some fast-tracking may entail looking very creatively at the network
diagram to see some discretionary dependencies could be done completely
independently.
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7.3 Logical schedule alternative

17. 2 - Crashing:
• Crashing is a schedule compression method that analyzes cost and schedule
tradeoffs to determine how to obtain the greatest amount of schedule
compression for the least incremental cost.
• Crashing typically involves allocating more resources to activities on the
critical path in an effort to shorten their duration and thereby increases
project costs.
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7.3 Logical schedule alternative

18. Schedule Tool:
– May include available commercial software or in-house, custom-built applications.
– Now you need to assign actual start and finish dates to each activity,
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7.3 Logical schedule alternative

19. 19
Schedule Baseline
A Schedule baseline is a specific version of the project schedule developed from
the schedule network analysis. It is accepted and approved by the project
management team as the schedule baseline
Schedule Data
Schedule data for the project schedule includes the schedule milestones, schedule
activates , activity attributes, and documentation of all identified assumptions and
constrains.
Supporting details include :-
- Resource requirements by time period
- Alternative schedules, such as best-case or worst case , not resource-leveled or
resource leveled
- Scheduling of contingency reserves
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7.3 Logical schedule alternative