220R89008
    EPA
    SYSTEMS DEVELOPMENT CENTER

Seminar Series:
          Designing and  Implementing
              an Information System
 Seminar No.2:
              ' Project Scheduling-
       A Project Managers Perspective9
                December 14, 1989
          EPA Education Center Auditorium

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      PROJECT SCHEDULING:
A PROJECT MANAGER'S PERSPECTIVE
          presented by

        Mr. Connie Teetz
  Planning Research Corporation

         December 14, 1989

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Seminar Objectives
     See where scheduling fits in the planning process



     Understand basic scheduling methods



     Be familiar with scheduling terminology
     Know what to look for in a schedule
     Recognize the value of automated scheduling tools

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Schedule
                                  GRAPHIC
                                 WORK PLAN
 A sequential plan to accomplish work. It focuses on
   the tasks to be done and the timing of each task.

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Setting the Foundation - Planning

     •  Determine the project objectives
     •  Break down the work into meaningful tasks
     •  Build a schedule
     •  Determine resource requirements
     •  Assign responsibility for the work
     •  Set up budgets
     •  Analyze risk
     •  Complete project plans

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The Project Plan - A Systematic Approach
     • An understanding of the objectives



     • Elimination or reduction in uncertainties



     • Improvement in efficiency



     • A basis to monitor performance



     • A baseline to manage change

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The Project Manager's Role in Project Planning
           Effective organization



           Comprehensive planning
           Realistic schedules
           Solid estimates/budgets



           Measurement of progress



           Allowance for timely recovery

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A Kev Step - Breaking Down the Work
       List the major tasks and deliverables



       Do a product oriented outline of the project



       Go to a level where work will be managed



       Set up a coding scheme



       Prepare short descriptions of work content

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           Medical Waste Information Project
INFORMATION MANAGEMENT SYSTEM CONCEPT
SYSTEM DESIGN / DEFINITION
SYSTEM DEVELOPMENT / IMPLEMENTATION
SYSTEM TESTING
TRANSPORTATION NOTIFICATION DATA BASE
MANAGEMENT TASKS

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The Functions of a Schedule
        Logical sequence of the work
        Includes all "events", both internal and external
        Facilitates resource planning
        Supports the budgeting process
        Highlights critical tasks
        Provides a "road map" for the project

      The schedule validates the project plan

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  Network Schedules - A Brief History
Program Evaluation and
Review Technique (PERT)
Arrow Diagramming
Method (ADM)
A statistical method using 3 or
more estimates for data input.
Term is used incorrectly to
refer to current network methods
            t
          Task
Precedence Diagramming
Method (PDM)
                                 Task
                Task

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Types of Schedules in Use Today
   Bar Chart (Gantt)
   Milestone Chart
                            H-l—i	1	h

                             I  L
   Network Diagrams

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Network Schedules - Loaic Diaarams
      Precedence Diagramming Method.... PDM
      - Activity-On-Node
      Arrow Diagramming Method..............  ADM
        Event-On-Node
           _  A
B
                                          -o

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Network Schedules - Terms
       Task (Activity)
       Event  -
       Milestone
       Imposed date
       Constraint
       Calendar
       Critical path
       Float
       Early start/finish
       Late start/finish

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Network Schedules - Constraints
     Constraints define the way tasks relate
     to one another - (dependencies)

     List the tasks and events of a network, then link
     them by drawing constraints
Predecessor

  "Go Before"
                               Successor
                               "X*WWWĞĞ*ĞW*>W<0ĞĞ*W^-!*W'WW

                                "Gome After"
                        Constraint

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Constraint Types
    Finish-to-Start    FS
    - Successor cannot start until predecessor finishes

     Start-to-Start     SS
    - Successor can start as soon as predecessor starts
    Finish-to-Finish    FF
    • Successor cannot finish until predecessor finishes
    Start-to-Finish    SF
    - Successor cannot finish until predecessor starts
G
                   B

7Tj

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  Network Schedules • Calculating Dates
Forward pass
Start from imposed start date and work forward
through the schedule adding the duration of
each activity along each path
Backward pass  Start with imposed end date and work backward
                through the schedule subtracting the duration of
                each activity along each path
             Imposed start

             ' EARLY
              START
        "Forward Pass"

        (Add Durations)
EARLY
FINISH
                          TASK
               LATE
               START
         "Backward Pass"

          (Subtract Durations)
  LATE
  FINISH
X	.	/

Imposed finish

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Network Analysis
      Attention focused on the identification of:
                 Critical Tasks
             ("Schedule Float / Slack  )
     -  Critical Tasks lie along the critical path ... a delay
       in any one of these tasks will impact the
       completion date of the project

     -  Critical Path ... timewise, the longest sequence
       of connected tasks through a network. Usually,
       the path with zero or negative float

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    Network Analysis
Concept
 Paper
  10|
System
Design
B   120
                                             Data
                                           Collection
                                              a
                    System
                  Development
                                   Interim
                                   Review
                                 D    3
 System
Installation
                                  System
                                  Testing
Data
Entry
                                                H   60
 Report
Generation
                                 J   I2°l
                            = Tasks
             [Critical Path |

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Network Schedules - Resource Scheduling
   Consider skills and/or specifications and mix/availability



   Initial estimates show usage profile and total usage



   A resource driven schedule may have different dates



   Usage profiles may cause overloads/underloads

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What Do You Need To Get Started?
      A list of milestones
      A list of tasks
      The period of performance



      Specific delivery/need dates
      A work calendar

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What Affects the Schedule?
      Durations
      Need dates
      Resource availability/limits



      Logic
      External events

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Information Needed  to Build a  Schedule
                Calendars
                 Project
                 Wortt
         Task Data

        Task Number
        Task Name
        Description
        Duration
 Resource
Information

 People
 Material
 Availability
    Other
Constraint Data

 Imposed Dates,
 Lag, Lead, etc.
                                    Task
                               Constraint Types
                                (Relationships)

                              FS  Finish-to-Start
                              SS  Start-to-Start
                              SF  Start-to-Finish
                              FF  Finish-to-Finish
                                  PRECEDENCE (PDM) NETWORK

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How to Track Progress

  Baseline Schedule

     Initial contractual work plan that is maintained
     for progress evaluations and trend analyses.
                            Focus  —*~  Planned Performance
  Current Status        J
     Current status causes changes in planned start/end
     dates. This may cause work-around plans and new
     projected completion dates
                            Focus  	*•- Deviations from Baseline
f Operating Schedule   ']
     Work plans that reflect work-around plans and new
     projected dates
                            Focus  —Ğğ-  Current Performance

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Baseline Schedule


 The approved plan for the accomplishment of project
 objectives.
 . Necessary in order to measure progress/ performance

 • Project manager should control any changes to the
   baseline schedule

 * The baseline schedule does not change when tasks slip

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Operating Schedule

 The current, updated project schedule used to manage
 ongoing tasks

    •  Used to project revised start & finish dates for
      all remaining tasks
      Useful management tool estimating the cost to
      complete the project

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As a Project Manager - What Questions Should You Ask?

  •  Are all tasks, milestones included?
  •  Are external events that effect the project included?
  •  Is the logic sound?
  •  Are the durations realistic?
  •  Are resource estimates accurate?
  •  Is resource utilization efficient?
  •  Is there any float (slack)?
  •  Is the level of detail appropriate?
  •  Can you understand the schedule?

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Automated Schedulina Tools
   They help in the process - You still make the decisions!
   They can help outline the work (break it down into tasks)
   Most use a Bar Chart (Gantt) format for input
   They require duration and logic
   They can be very helpful in resource leveling
   They work best when you keep the number of activities low
   Great for "what if" exercises
   Know your requirements before you pick one

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Summarv
   Scheduling is a key element in the planning process



   As a project manager, you play a very important role



   Know what to look for in a good schedule



   Use the schedule as a management tool



   Automated tools don't replace decisions

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                 SCHEDULING TERMINOLOGY

Activity - See Task

Arrow Diagramming Method (ADMj

     A networking technique in which a task is shown as
     an arrow between two nodes representing events.
     Constraints are depicted as node-to-node
     relationships.  Also known as Activity-on-Arrow or
     I-J (Interface-Juncture) method.

As Late As Possible (ALAP)

     A scheduling technique in which the task schedule
     is computed by starting with its due date and
     working backward to determine the required start
     date. An ALAP task is scheduled immediately before
     its first successor. Also known as backwards
     scheduling.

As Soon As Possible

     A scheduling technique in which the task is
     scheduled forward in time from the project start
     date to determine the required finish date. An
     ASAP task is scheduled immediately after its last
     predecessor. Also known as forwards scheduling.

Backward Pass

     The procedure to establish when tasks and events
     must happen by calculating late start and finish
     dates with respect to project requirement dates
     such as the completion date.

Barchart

     A format for displaying schedule data in which a
     task's planned time span is depicted as an open
     horizontal bar the ends of which correspond to the
     scheduled start and finish dates. The task's
     progress toward completion is shown by blackening
     the open bar along the time scale. Also known as a
     Gantt chart, named for Henry Gantt who first used
     the scheduling method in the early 1900's.

Baseline

     A set of original or approved schedule dates that
     can be compared to actual start and finish dates
     to determine project status in relation to plan.

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Calendar
     The definition of work periods (hours, days,
     weeks,  months, years) and non-work periods
     (weekends, holidays, vacation time for labor
     resources)
Coding
     Application of unique identifiers to permit
     sorting and selection of data and maintain
     traceability of a task within the network data
     base or between multiple linked data bases.
Constraint
     A quantifiable relationship that ties network
     tasks and events together. Constraints both
     establish (task A cannot start until task B
     finishes) and qualify (task A can finish 2 weeks
     after receiving the output of task B)
     relationships among tasks. Also known as
     Dependency and Link. The following four constraint
     types are used to designate these relationships:

          o    Finish-to-start (FS) - Task A
               (predecessor)  must finish before Task B
               (successor) can start. This is the most
               commonly used constraint type.

          o    Start-to-Finish (SF) - Task A
               (predecessor)  cannot finish before Task
               B (successor)  is started. This is the
               least commonly used constraint type.

          o    Finish-to-Finish (FF) - Task B
               (successor) cannot finish before Task A
               (predecessor)  is finished. A time value
               is sometimes applied to reflect the
               amount of work that Task B needs to
               accomplish after it receives the output
               of Task A.

          o    Start-to-Start (SS) - Task B (successor)
               cannot start before Task A (predecessor)
               is started. A time value is sometimes
               applied to reflect the amount of work
               Task A must accomplish before Task B can
               start.

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Critical
     Any task with zero or negative float. Critical
     tasks are those in which any delay in the task
     will delay the completion of the project.

Critical Path

     The longest (with respect to the total time
     available) path of sequential tasks with the least
     amount of float in the network. The critical path
     is that string of tasks and events where a delay
     in accomplishing any one of them will jeopardize
     on-time completion of the project.

Critical Path Method

     An analytical technique used to identify real or
     potential time reserve, predict the impact of
     critical task performance problems and evaluate
     the schedule impact of proposed solutions.
Delay

     A time delay in a constraint indicating that tasks
     are constrained in the middle rather than the
     start or finish of their span time. Delay in a
     start-to-start constraint is a portion of the
     duration of the predecessor task, while delay in a
     finish-to-finish constraint represents part of the
     successor's duration. Delay may also be used to
     limit the number of scheduled tasks as in the case
     where shipping is considered a two-week lag in the
     constraint between production and installation
     tasks. See also Lag and Lead.

Dependency - See Constraint.

Dummy

     A task that can be used to build the network
     logic, but which does not represent any real work
     and cannot have resources applied against it; a
     really stupid person.

Duration

     The amount of time required to start, perform and
     complete a task. Applying numerical values for
     duration to a task logic flow transforms it to a
     task network.

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Duration-Driven Scheduling

     Scheduling only according to the time period
     required for work accomplishment without regard
     for resource requirements.

Earlv Finish

     The earliest date on which a task can be completed
     as determined by network time analysis.

Earlv Start

     The earliest date on which a task can be started
     as determined by network time analysis.

Effort-Driven Scheduling - See Resource-Driven
Scheduling.
End
     A task with no logical successors; the last task
     in the network.
Event
     An instant of time indicating the start or finish
     of a task or a project milestone; see also Imposed
     Date.
Float
     The time value difference between when tasks can
     happen (early start/early finish) and when the
     must happen (late start/late finish). Also known
     as SJ.ack or time reserve. Float is that amount of
     time that tasks can slip without delaying other
     tasks in the schedule. See also Free Float and
     Total Float.
Forward Pass
     The forward computation procedure for establishing
     the earliest expected start and finish dates for
     tasks (early start/early finish) based on their
     durations and constraints.

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Free Float

     The amount of time a task may be delayed without
     affecting any of its successor tasks.

Gantt Chart - See Bar Chart.

Hammock

     A technique for summarizing detailed tasks or
     subnetworks where start and finish events
     represent the earliest start and latest finish of
     a set of tasks.

Histogram

     A vertical barchart where resource utilization
     rates are displayed vertically across a horizontal
     time scale.

Imposed Date

     A "due by" or "need by" date established
     independently of the network development process.
     Project milestones are generally established as
     imposed dates.
Lag
     The amount of time after a predecessor task
     finishes that a successor task can start in a
     finish-to-start relationship. See also Delay.
Late Finish
     The latest date a task can complete without
     affecting any successor tasks or the project
     completion date.
Late Start
     The latest date a task can start without affecting
     any successor tasks or the project start date.
Lead
     The amount of time before a predecessor task
     finishes that a successor task can start in a
     finish-to-start relationship. See also Delay.

Link - See Constraint.

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Logic Diagram
     Graphic depiction of the relationships among tasks
     that shows the sequence and flow of project work;
     generally a logical layout of the project WBS
Loop
     A network logic error in which tasks are so
     constrained that it is impossible to perform a
     time analysis because each task is its own
     predecessor and/or successor.

Master Schedule

     A schedule depicting the entire project plan,
     generally at a summary level. The master schedule
     may be displayed in either barchart or network
     diagram formats.

Milestone

     A key occurrence in the project schedule such as
     project start, design reviews, delivery date and
     project finish. Generally scheduled as a zero
     duration event. See also Event and Imposed Date.

Negative Float

     The result of a condition where a task's early
     dates are later than its late dates; insufficient
     time to complete the task; also known as negative
     slack.

Network Diagram

     A flow chart of the project plan showing task
     durations, constraints and the critical path.

PERT Analysis

     A method of computing expected task duration where
     the weighted average of optimistic, most likely
     and pessimistic duration estimates is determined.
     PERT is the acronym for Program Evaluation and
     Review Technique developed for the Polaris
     submarine program in the 1950's.

Percent Complete

     A measure of work accomplishment that compares the
     amount of effort completed with the total task
     effort to be completed; also known as physical
     percent complete.

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Positive Float

     The result of a condition where a task's early
     dates are earlier than its late dates; more than
     adequate time to complete the task; also known as
     positive slack.
Precedence Diagramming Method fPDM)

     A networking technique where tasks are represented
     by nodes (rectangular boxes) and constraints are
     shown as lines between the nodes. Also known as
     Activity on Node.

Predecessor

     A task or event that logically flows into another
     activity or event.

Project

     A set of tasks that must be performed to reach a
     specified objective.

Resource

     People and material required to accomplish a task.

Resource Allocation

     The process of assigning resources to a task.

Resource Conflict

     A condition in which a resource workload exceeds
     its availability; also known as resource overload.

Resource-Driven Scheduling

     A scheduling method that determines task durations
     based on the amount of resources available for
     task accomplishment.

Resource Leveling

     Delaying tasks in the scheduling process until the
     required resource is available; scheduling so as
     not to exceed the availability of required
     resources.

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Resource Pool
     A set of resources that may be shared among
     several projects.
Selection

     Derivation of only specified schedule data that
     meets defined criteria. For example, selection of
     only those tasks with an early finish date before
     a required delivery date.

Slack - See Float.

Sort

     To order in a specified manner. For example, a
     sort by early start would list the earliest task
     first followed by the next chronological task.
     Any task without a constraint into its start.

Successor

     A task or event that logically follows another
     task or event.

Target Date - See imposed Date

Task

     Performance of effort in terms of resources
     required over a specified period of time;
     generally the smallest unit of work that can be
     scheduled; also known as an Activity.

Time Analysis

     The process of running a forward and backward pass
     through the network to determine early start/early
     finish and late start/late finish dates for each
     task.

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Total Float
     The amount of time a task can be delayed without
     affecting the completion date of the project.
Zero Float
     The result of a condition where a task's early
     dates are equal to its late dates; just enough
     time to complete the task; also known as zero
     slack.

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