CPETECET 470 Project Management

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CPET/ECET 470Project Management

• Class 3 - Critical Path

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Myth 4

• I dont need a schedule, because I already know
  what needs to be done.
• Maybe you do
• However, you need the schedule to communicate to
  others what needs to be done
• The team needs a vehicle to keep you informed of
  their plans

LESSON The schedule is a communication tool
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Top Level Schedules 5 Easy Steps

• List Program Tasks
• Brainstorming is a good method to generate this
  list
• All schedules should follow the WBS
• Note Updates to the WBS should be expected as a
  result of the scheduling process.
• Start with major deliverables and key milestones
• Sequence Tasks
• This is simply putting the tasks in the order
  they will occur
• Identify Relationships between tasks
• This requires team members who are cognizant of
  the processes involved
• Assign Durations to Tasks
• Analyze plan against program objectives

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Myth 5

• I dont have to put that task on the schedule.
  It is inferred from the phase of the program that
  it occurs in.
• Inference is based on your level of cognizance at
  the that time. Others will be using the schedule
  to manage their work
• Program team members change throughout the life
  of the program
• All program efforts must be on the plan at some
  level
• If it is not on the schedule, it will likely be
  forgotten .until it is too late, causing
  regression

Truth The schedule should document the plan
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Schedule Analysis

• What is schedule analysis?
• Identifying the Critical Path
• Forward and backward pass analysis
• Identifying slack

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Analyze the Plan

• It is important to analyze any plan to determine
• The overall health of the plan
• Level of detail
• Proper scheduling techniques applied
• Compliance with significant milestones
• The viability of the plan
• Amount of margin in the plan
• Areas of the plan that require action
• Current and potential problem areas
• Progress against the plan
• Schedule position

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Myth 6

• I do not need a schedule because I already know
  what the critical path is.
• You may have a sense of what the critical path is
• When you prepare a detailed schedule, items that
  you did not expect or were not watching will
  surface on the critical path
• Action must be taken to move these items off the
  CP
• The individuals performing the work will plan for
  details that you may not be aware of

Truth The critical path must be managed, not
dictated
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The Critical Path Definition

• A set of activities which determine the earliest
  completion of the project, where any delay in any
  activity will delay the project by an equivalent
  amount
• The path(s) in the task network with zero slack
• The path with the longest duration through the
  network

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Critical Path Exercise

• Sum the times along each path in a network to
  determine the overall duration of each path.
• The longest path in the network is the critical
  path.
• The project cannot end before the critical path
  ends.
• What is the critical path of the following
  network?
• How long will this project take to complete?

Task G 6 days
Task C 3 days
Task A 3 days
Task D 7 days
Task H 1 day
Task F 5 days
Task E 4 days
Task B 2 days
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Critical Path for an Entire Project

• All tasks are compared to the latest task in the
  project. If a delay in a task would impact this
  date then the task is considered critical

Critical Path 0 7 5 4 0 16 days
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Critical Path for multiple sets of tasks

• Each chain of tasks calculates critical path
  separately within its own set of tasks. A
  critical path is calculated for each finish task
  within the project. A task is considered
  critical if it impacts the end of its network of
  tasks.
• The example shows two chains of connected tasks
  within a single project, each calculating
  critical path from the finish tasks.

Critical Path 0 7 5 4 0 16
days Critical Path 0 6 9 15 days
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Critical Path Analysis (CPA)

• The Key Concept used by CPA is that a subset of
  project activities, which make up the longest
  path through the activity network, control the
  entire project
• If these "critical" activities could be
  identified and assigned to responsible persons,
  management resources could be optimally used by
  concentrating on the few activities which
  determine the fate of the entire project
• Non-critical activities can be replanned,
  rescheduled and resources for them can be
  reallocated flexibly, without affecting the whole
  project
• There are three steps to performing Critical Path
  Analysis
• Forward Pass
• Backward Pass
• Float Calculation

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Forward Pass

• The forward pass is calculation of the Earliest
  Start and Earliest Finish dates for each task in
  the network
• Early Start Date the date at which the task's
  predecessors have all been completed
• Early Finish Date the Early Start Date plus the
  task duration
• A typical format of reflecting these dates in a
  network is

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Forward Pass - Exercise

• Start with the first task in the path and
  calculate the Early dates
• Assume the project starts on Day 1 of the Project

ES
EF
ES
EF
Task G 6 days
Task C 3 days
ES
EF
Task A 3 days
ES
EF
ES
EF
Task H 1 days
Task D 7 days
ES
EF
Task F 5 days
ES
EF
ES
EF
Task B 2 days
Task E 4 days
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Forward Pass - Exercise

• Start with the first task in the path and
  calculate the Early dates
• We will do the first two tasks together

Day 4
Day 6
ES
EF
Task G 6 days
Task C 3 days
Day 1
Day 3
Task A 3 days
ES
EF
ES
EF
Task H 1 days
Task D 7 days
ES
EF
Task F 5 days
ES
EF
ES
EF
Task B 2 days
Task E 4 days
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Backward Pass

• The backward pass is calculation of the Latest
  Start and Latest Finish dates for each task in
  the network
• Late Start Date the date after which the task
  causes slippage of the project end date. It is
  determined by starting at the end of the project
  and working backwards
• A typical format of reflecting these dates in a
  network is

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Backward Pass - Exercise

• Start with the last task in the path and
  calculate the Latest Dates
• The Early Finish of the last task on the CP is
  equal to its Latest Finish

LS
LF
LS
LF
LS
LF
LS
LF
LS
LF
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Backward Pass - Exercise

• Start with the last task in the path and
  calculate the Latest Dates
• We will do the first two tasks together

Day 7
Day 12
Task G 6 days
Day 10
Day 15
LS
LF
Day 16
Day 16
LS
LF
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Forward and Backward Pass

• Review the Critical Path
• What do you Notice about the Early and Late Dates?

EARLY DATES LATE DATES on the CRITICAL PATH
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What is slack?

• The time between a tasks planned completion date
  and its need date
• The time available to delay the completion of an
  activity without impacting the project end date
• Useful to help to determine the impact of tasks
  slippage on the overall program schedule
• Slack is used to prioritize tasks for resource
  allocation (the less slack, the higher the tasks
  priority because it is more critical)
• The difference between a tasks Earliest dates
  and its Latest Start / Finish dates
• Also referred to as Float

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SLACK Calculation - Exercise

• How much Slack (or Float) does each task have?
• Slack LF - EF

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Class 3 Assignment

• Complete handout
• Due Monday
• Use Microsoft Project to assist you in providing
  answers if you want (good practice to learn the
  software)
• Read paragraphs 15.4 15.5