1. Lecture 3.5: Work Dependencies, Scheduling, IMP & IMS (SEF A16A)
Dr. John MacCarthy
UMBC CMSC 615
Fall, 2006

2. 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

3. Types of Schedules Event-Based Schedule: “Time-Expressed” 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

4. Event-Driven Schedules
DoDI 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

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

6. “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

7. 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)

8. 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

9. 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

10. “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

11. 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

12. 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

13. 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

14. 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