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Lecture 3.5: Work Dependencies, Scheduling, IMP & IMS (SEF A16A)

Dr. John MacCarthyUMBC CMSC 615Fall, 2006

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Agenda Types of Schedules Event-Driven Schedules Events and Entry/Exit Criteria Resource Loaded Schedules Integrated Management Plan (IMP) Example PERT Chart “Time-Expressed” Schedules Integrated Management Schedule (IMS) Example Gantt Chart Scheduling Tools Summary

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Types of Schedules Event-Based Schedule:

Generally referred to as the Integrated Management Plan (IMP) Generally implemented as a Program Evaluation and Review Technique (PERT)

Chart Identifies key engineering management events and relates them to the WBS Identifies the key tasks and results expected to permit key events Identifies key dependencies between tasks and events Serves as basis for:

Schedule Control Resource (& Cost) Control & Prioritization Planning & Measuring Cost/Schedule Progress, i.e. Earned Value A valid time-based (detailed) schedule

“Time-Expressed” Schedule: Generally referred to as the Integrated Master Schedule (IMS) Generally implemented as a Gantt Chart Provides dates

For key events By which tasks are to be started and ended

Shows key temporal dependencies between tasks and events Resource loaded time-based schedules serve as basis for Earned Value

Measurement Generally derived from the Event-based Schedule (PERT Chart)

Note that my (and industry) usage of the term IMS is inconsistent with the SEF use of term

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Event-Driven Schedules DoDI 5000.2 indicates schedules

should be “EVENT-DRIVEN,” not “Time-Driven”:

Do not let a date on a schedule force an event,

The successful completion of event entry/ exit criteria should drive when an event occurs

The Integrated Management Schedule (IMS) is DoD “Event-Driven” Schedule (generally represented as a PERT Chart)

Process: Identify key events required to achieve

programmatic success Identify entry/exit criteria for those

events Identify tasks that must be performed to

satisfy entry/exit criteria Identify dependencies between tasks

and events Identify time to accomplish required

tasks (to satisfy entry/exit criteria) (Time) Schedule the events (and tasks)

accordingly

Key SE Events: SRR SFR PDR/SSR CDR/TRR SVR/FCA PCA

Key Events generally have documented Entry and Exit Criteria

Reality Check - All programs have real end dates associated with them. If the time-schedule derived from the event-schedule does not meet the required end date:

Entry/exit criteria may need adjustment

Task & task estimates may need adjustment

Customer may need to revise end-date

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Example Event Exit Criteria

Events have associated (Entry and) Exit Criteria Events should not occur until (Entry and) Exit Criteria can be met

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“Event-Based Schedule” Development

Identify what artifacts/ products (& associated tasks) need to be complete for each WBS element for each Event

Identify artifact/ product/ tasks dependencies

Provides basis for Earned Value

Graphic provides one example of how this can be done

Each program will have its own process and forms

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Example PERT Chart A PERT Chart is essentially a flow chart showing the dependencies

between events and activities (what activities need to be completed prior to what events and the complete/start dependencies between activities)

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Integrated Management Plan (IMP)

The IMP is. The IMP is generally used to develop a

schedule by fixing Customer dictated Event dates and determining the time required to complete required activities.

Generally the IMP takes the form of a (PERT) Chart

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Resource Loading of Schedules

Generally one identifies the following data for each task (to develop artifacts and support events):

Event(s) Supported WBS Reference (WBS Element and Work Package) Start Date End Date EV milestones and credit Task Dependencies (input/output) Resources required (generally staff months and skill type)

As such, the data exists to “resource load” the schedule As one transitions from an “event-based” schedule to a “time-based”

schedule, one can determine the (time-phased) staffing profile for the program, i.e., how many people (full time equivalents (FTEs)) are required (with what skills) as a function of time

Note: For a given amount of work, as the schedule is compressed, the number of FTEs required (for each skill set) will increase.

Note: Schedule compression and elongation each result in (different) inefficiencies that drive up the resource count

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“Time-Expressed” Schedules

In order to manage a program, one must eventually assign dates to Events and Tasks

The result is a “Time Expressed” or “Calendar-Based” Schedule

This is usually represented by a Gantt Chart

Time-Expressed Schedules are generated from the IMS

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Integrated Master Schedule (IMS)

Technically the IMS is a database that includes:

All Milestones/ Events All Activities/Tasks &

Activity/Task start/stop dates All Activity/Task & Event

dependencies WBS/Work Package References Often associated WBS/Work

Package information such as staff loading and cost

The IMS is almost never seen in its entirety, rather different “Views” of the IMS are provided depending on the purpose

The views are generally provides as “Gantt Charts”

Levels/Views of the IMS: Top-Level:

Major Milestones/Events, Activities, & Dependencies

Used by Top Management and the Customer Shown at Technical Reviews and PMRs

Total Detailed (the “Real”) IMS: All Milestones/Events, Activities, & Dependencies Provides basis for other views Rarely seen by anyone

IPT Mid-Level: Major Milestones/Events, Activities, &

Dependencies of interest to an IPT Used by IPT Manager Shared with IPT and Management

Work Package Detailed: All Milestones/Events, Activities, & Dependencies

associated with a given work package Developed & Used by Work Package Lead Shared with Mid-level management Serves as building block for Total Detailed (“Real”)

IMS

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Gantt Chart Example A Gantt Chart

represents: Events as “Taco Chips” Activities as “bars” Dependencies as

“arrows” Each Event and Activity

is labeled as a Row Events & Activities may

be Decomposed/Nested The date of an Event and

the duration each activity is indicated by its location in the Row

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Scheduling Tools Generally the IMP and IMS will be developed in a single tool that:

Permits one to develop a Event-Driven IMP “Schedule” (as a PERT Chart) Events & Activities Dependencies

Include WBS/Work Package References Enter planned and actual Resource Loading data Enter planned and actual cost data Enter planned and actual start/stop dates for events & activities Permits one to generate the Time-Expressed IMS & IMS Views (as Gantt

Charts) Permits one to generate planned and actual Resource Profiles Permits one to generate an Earned Value Report

Examples: MS Project

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Summary Schedules should be “Event-Based” Events should not occur until all Entry and Exit Criteria are

fulfilled The IMP is an Event-Based Schedule that is often represented

as a PERT Chart Events and activities in an IMP should be tied to the WBS Schedules need to be “Time-Expressed” The IMS is a database that includes Time-Expression The Gantt Chart provides a IMS may be viewed in a Time-

Expression Schedules are generally Resource Loaded Tools exist for the development of IMPs and IMSs that may

also be used to generate Earned Value Reports and Resource Profiles