–
Processes
required to ensure timely completion of the project
–
No
consensus concerning differences between activities and tasks
–
Activities
seen as composed of tasks –most common usage
–
Other
disciplines have tasks composed of activities
(Click
above for PMBOK4 Article)
•
Activity
Definition: identifying and documenting specific activities to produce project
deliverables identified in the WBS
–
Must
be defined to meet the project objectives
•
Activity
Definition Inputs
–
WBS
– primary input
–
Scope
Statement – project justification & project objectives
–
Historical
Information
–
Constraints
–
Assumptions
•
Activity
Definition Tools & Techniques
–
Decomposition
– outputs are expressed as activities rather than deliverables
–
Templates
– reuse from previous projects
•
Activity
Definition Outputs
–
Activity
List – all to be performed; extension to the WBS and includes description to
ensure team members understand work to be performed
–
Supporting
Detail – organized as needed and include all assumptions and constraints
–
WBS
Updates – identify missing deliverables and clarify deliverable descriptions.
WBS updates often called refinements; more likely using new technologies in
project
•
Activity
Sequencing – identifying and documenting interactive dependencies among
activities. Support later development of
a realistic schedule
–
Project
Management software often used
•
Activity
Sequencing Inputs:
–
Activity
List
–
Product
Description – product characteristics often affect activity sequencing
–
Mandatory
Sequencing – physical limitations, hard logic, prototypes needed; inherent in
nature of work being done
–
Discretionary
Dependencies – defined by project management team; “best practices” or unusual
aspects of project – soft logic, preferred logic, preferential logic
–
External
Dependencies – relationship between project activities and non-project
activities (company policies,
procurement, etc.)
–
Constraints
–
Assumptions
•
Network
Diagrams
–
Shows
how the project tasks will flow from beginning to end
–
Proves
how long the project will take to complete
–
Takes
project tasks from low levels of WBS and placing them into their order of
completion (beginning to end)
•
Activity
Sequencing Tools & Techniques
–
Precedence
Diagramming Method (PDM) – constructing network diagram using nodes to represent
activities and arrows to indicate dependencies; also called Activity On Node
(AON)
–
Most
project management software uses
–
Includes
4 types of dependencies:
•
Finish
to Start – “from” activity must finish before “to” activity can begin; most
commonly used
•
Finish
to Finish – “from” activity must finish before the next may finish
•
Start
to Start – “from” activity must start before next “to” activity can start
•
Start
to Finish – task must start before next
activity can finish
–
Use
caution with last 3 techniques - logical
relationships often not consistently implemented with project management
software
–
Arrow
Diagramming Method (ADM) – uses arrows to represent activities and connecting
at nodes to illustrate dependencies
•
Also
called Activity On Arrow (AOA)
•
Only
uses finish to start dependencies
•
PERT
and CPM only can be drawn using AOA
–
Conditional
diagramming methods
•
GERT
(Graphical Evaluation and Review Technique)
•
System
Dynamic Models
•
Allow
for non-sequential activities (loops) or conditional branches – not provided by
PDM or ADM methods
–
Network
Templates – standardized networks can be used. Composed of subnets, or fragnets
•
Subnets
are several nearly identical portions of a network (floors on a building,
clinical trials, program modules)
•
Useful
for several identical processes (clinical trials, programming modules).
•
Activity
Sequencing Outputs:
–
Project
Network Diagram – schematic display of project activities and relationships
(dependencies). Should be accompanied by a summary narrative that describes the
diagram approach
–
Activity
List Updates
•
Activity
Duration Estimating
–
Involves
assessing number of work periods needed to complete identified activities
–
Requires consideration of elapsed time, calendars,
weekends, and day of week work starts
•
Activity
Duration Estimating Inputs:
–
Activity
Lists
–
Constraints
–
Assumptions
–
Resource
Requirements – amount of labor assigned to activity
–
Resource
Capabilities – human and material resources, expertise
–
Historical
Information
•
Project
Files, or records of previous project results
•
Commercial
Duration Estimates – useful when durations are not driven by actual work
(approval periods, material resources)
•
Project
Team Knowledge
•
Activity
Duration Estimating Tools & Techniques
–
Expert
Judgment – guided by historical information should be used whenever possible;
high risk without expertise avail.
–
Simulation
– using different sets of assumptions (Monte Carlo Analysis) to drive multiple
durations
–
Analogous
Estimating – “top down estimating” – use actual, similar, previous known
durations as basis for future activity duration. Used when limited knowledge is available.
Form of expert judgment
•
Activity
Duration Outputs:
–
Activity
Duration Estimates – quantitative assessments of work periods to complete an
activity. Should indicate a range +/- of
possible results
–
Basis
of Estimates – all assumptions should be documented
–
Activity
List Updates
•
Schedule
Development
–
Determining
start and finish dates for project activities
–
Without
realistic dates, project unlikely to be finished as scheduled
–
Schedule
development process often iterates as more information becomes available
(process inputs)
•
Schedule
Development Inputs:
–
Project
Network Diagram
–
Activity
Duration Estimates
–
Resource
Requirements
–
Resource
Pool Description – availability patterns; shared resources are highly variable
–
Calendars
– define eligible work periods
•
Project
Calendars affect all resources
•
Resource
Calendars – affect specific resource pools or individuals
–
Constraints
•
Imposed
Dates – may be required
•
Key
events or milestones – are initially requested and become expected during
project
–
Assumptions
–
Lead
and Lag Time – dependencies may specify time in order to satisfy relationship
(example – 2 weeks to receive order)
•
Schedule
Development Tools & Techniques
–
Mathematical
Analysis – calculating theoretical early/late finish and start dates without
regard for resource pool limitations; indicate time periods which activity
should be scheduled given resource limits and other constraints:
•
Critical
Path Method (CPM) – single early/late start and finish date for all activities.
Based on specified, sequential network and single duration estimate. Calculates
float to determine flexibility
•
Graphical
Evaluation and Review Technique (GERT) – probabilistic treatment of network and
activity duration estimates
•
Program
Evaluation and Review Technique (PERT)- sequential network and weighted average
duration to calculate project duration –
differs from CPM by using mean (expected value) instead of most-likely estimate
in CPM
•
Schedule
Development Tools & Techniques
–
Critical
Path Method: refers to estimating based on one time estimate per activity
•
One
time estimate per task (Most Likely)
•
Emphasis
on controlling cost and leaving schedule flexible
•
Drawn
using AOA diagrams
•
Can
have dummy task
–
PERT
(Program Review and Estimating Technique)
•
3
Time estimates per activity
•
Optimistic
•
Pessimistic
•
Most
Likely
•
Emphasis
on meeting schedule, flexibility with costs
•
Drawn
on AOA diagrams
•
Can
have dummy tasks
•
Schedule
Development Tools & Techniques
–
Monte
Carlo Analysis
•
Uses
a computer with PERT values and network diagram
•
Tells
•
Probability
of completing a project on any specific day
•
Probability
of completing a project for any specific amount of cost
•
Probability
of any task actually being on the critical path
•
Overall
Project Risk
•
Suggests
that Monte Carlo simulation will create a project duration that is closer to
reality than CPM or PERT
–
Duration
Compression – look to shorten project schedule without affecting scope
•
Crashing
– cost and schedule trade-offs to determine greatest amount of compression for
least incremental cost – often results in higher costs
•
Fast
Tracking – performing activities in parallel that normally would be sequenced –
often results in re-work and usually increases risk
–
Simulation
–
Resource
Leveling Heuristics – leveling resources that apply to critical path activities
a.k.a. “resource constrained scheduling” – when limitation on quantity of
available resources; sometimes called “Resource Based Method” – often increases
project duration
–
Project
Management Software
–
Project
Manger’s role
•
Provide
the team with the necessary information to properly estimate the task
•
Complete
a sanity check of the estimate
•
Formulate
a reserve
–
Project
Team should be involved; determine task estimates
•
Historical
Records
•
Guesses
•
Actual
Costs
•
Benchmarks
•
CPM
and PERT
•
Schedule
Development Tools & Techniques
–
Critical
Path Method: longest path through a network diagram and determines the earliest
completion of the project
–
Proves
how long the project will take
–
Indicates
tasks that need most monitoring
–
Almost
always have no slack
•
Schedule
Development Outputs:
–
Project
Schedule – includes planned start and finish dates for each activity; remains
preliminary until resources assignments are approved. Usually in following formats:
•
Project
Network Diagrams (with date information added) – show logical and critical path
activities
•
Bar
or Gantt charts – activity start and end dates, expected durations
•
Milestone
Charts – identifies key deliverables and interfaces
•
Time-scaled
network diagrams – blend of project network and bar charts
–
Supporting
Detail – all assumptions and constraints.
May also include:
•
Resource
requirement by time period (resource histogram)
•
Alternative
schedules (best/worst case)
•
Schedule
reserve/risk assessments
–
Schedule
Management Plan – how updates are managed
–
Resource
requirement updates – leveling and activity impact
•
Schedule
Control:
–
Influencing
factors which create schedule changes to ensure changes are beneficial
–
Determining
that schedule has changed
–
Managing
actual changes as they occur
•
Inputs
to Schedule Control
–
Project
Schedule – baseline approved, measure against project performance
–
Performance
Reports – planned dates met, issues
–
Change
Requests
–
Schedule
Management Plan
•
Schedule
Control Tools & Techniques
–
Schedule
Change Control System – defines procedures for schedule changes, paperwork,
approval, tracking systems
–
Performance
Measurement – assess magnitude of variations to baseline; determine if
corrective action is needed
–
Additional
Planning
–
Project
Management Software
•
Schedule
Control Outputs:
–
Schedule
Updates – any modifications, stakeholder notification
•
Revisions
change scheduled start and finish dates – generally in response to scope
changes. “Re-baselining” may be needed
in drastic situations
–
Corrective
Action – re-align performance with project plan
–
Lessons
Learned
•
Key
knowledge points not in PMBOK
–
Need
to know manual calculations of network diagrams
•
Created
after project charter and WBS (task estimates and dependencies are determined)
•
Mandatory
dependencies (Hard Logic) – inherent in nature of work
•
Discretionary
dependencies (Soft Logic) – based on experience, desire or results
•
External
dependencies – based on needs and desires of organizations outside the project
•
Methods
to draw network diagrams
–
Activity
on Node (AON) or Precedence Diagramming Method (PDM)
•
Boxes
represent tasks
•
Arrows
show task dependencies
•
4
types of task relationships
•
Finish
to Start (task must finish before next can start)
•
Finish
to Finish (task must finish before next can finish)
•
Start
to Start (task must start before next can start)
•
Start
to Finish (task must start before the next can finish)
•
No
dummy tasks used
•
Methods
to draw network diagrams
–
Activity
on Arrow (AOA or Arrow Diagramming Method (ADM)
•
Arrows
used to represent tasks
•
Only
Finish to Start relationships are used
•
May
use dummy tasks (show dependencies)
•
PERT
and CPM estimating techniques can only be drawn using AOA
•
CPM
(Critical Path Method) – estimating based on one time estimate per activity
(the most likely time estimate)
•
Emphasizes
controlling cost and allowing schedule flexibility
•
Can
have dummy tasks
•
PERT
(Program Evaluation and Review technique)
•
3
time estimates per activity: Optimistic (O), Most Likely (M), Pessimistic (P)
•
Emphasizes
meeting schedule, flexibility with cost
•
Can
have dummy tasks
–
Estimating
based on 3 formulas:
•
PERT
Duration: (P + 4M + O)/6
•
Standard
Task Deviation: (P – O)/6
•
Task
Variance:
•
Total
project estimate:
•
Add
up all Optimistic, Most Likely and Pessimistic values of the critical path
tasks and apply P + 4M + O/6
•
Total
project variance (+/-):
•
Add
up the individual task variances and take the square root of the value. Use the
value as a +/- figure to compute the Optimistic and Pessimistic values. The
total project estimate will serve as the basis.
•
Monte
Carlo Simulation:
–
Uses
a computer with PERT values (P, M, O) and a network diagram but does not use
the PERT formula
–
Indicates
•
Probability
of completing project on a specific day
•
Probability
of completing project for any specific amount of cost
•
Probability
of any task actually being on critical path
•
Overall
project risk
•
Estimating
techniques in general:
–
Should
be performed by entire project team
•
Project
manager needs to provide information to allow team to create estimates; sanity
check; formulate reserve
–
Estimates
are:
•
Guesses,
Historical Records, Actual Costs, Benchmarks, CPM, PERT
•
Critical
paths determines the earliest completion date and identifies tasks that need
monitoring
•
Can
be obtained by CPM, PERT and Monte Carlo estimating techniques
•
Key
Definitions:
–
Slack
(Float): the amount of time a task can be delayed without delaying the entire
project. Tasks on critical path have no slack.
•
Slack
is calculated by the difference between Early Start and Late Start of a task
•
Free
Slack (Float): the amount of time a task can be delayed without delaying the
early start date of its successor
•
Total
Slack (Float): the amount of time a task can be delayed without delaying the
project completion date
–
Lag:
inserted waiting time between tasks
•
General
Comments:
–
Projects
can have more than 1 critical path (increases risk) and can involve dummy tasks
–
Negative
float indicates that you are behind
–
Resource
Leveling involves possibly letting schedule and cost slip
–
Heuristics
– just means “rule of thumb” e.g. 80/20 rule
–
Schedules
are calendar based – makes this different than a time estimate
•
Bar
Chart a.k.a. Gantt chart (track progress, report to entire team including
stakeholders, control tool)
•
Network
Diagram (to show task inter-dependencies, show project organization, basis for
project control)
•
Milestone
chart (report to Senior management, shows major events)
•
General
Comments:
–
To
shorten project schedule examine the critical path
•
Crashing
– add more resources to the critical path tasks
•
Usually
results in increased cost
•
Fast
Tracking – performing tasks in parallel
•
Can
result in re-work and increased risk
–
Best
to select method that has least impact on the project (is the importance on
cost, risk or schedule?)
•
General
Comments:
–
Bar
(Gantt) Charts
•
Weak
Planning Tool, effective progress and reporting tool
•
Does
not show interdependencies of tasks
•
Does
not help organize the project more effectively
–
Network
Diagrams (PERT, CPM, PDM)
•
Shows
task interdependencies
•
Aids
in effectively planning and organizing work
•
Provides
a basis for project control
–
Milestone
Charts
•
Only
shows major events
•
Good
for reporting to management and customer
–
Flow
Charts
•
Depicts
workflow and not commonly used for project management
–
Free
Slack (Float) – amount of time a task can be delayed without delaying the early
start date of its successor
–
Total
Slack (Float) – amount of time a task can be delayed without delaying the
project completion date
–
Lag
– inserted waiting time between tasks
•
Resource
Leveling – level peaks of resource usage; stable number of resources – allows
schedule and cost slip in favor of leveling resources
•
Heuristic
– rule of thumb (80/20 rule)
