PRT-57, 21 Nov 2010

Measuring Schedule Performance NASA Project Management Challenge 2011

8 - 10 February 2011

Tony Harvey

Measuring Schedule Performance NASA Project Management Challenge 2011

8 - 10 February 2011

Tony Harvey

Los Angeles Washington, D.C. Boston Chantilly Huntsville Dayton Santa Barbara

Albuquerque Colorado Springs Ft. Meade Ft. Monmouth Goddard Space Flight Center Ogden Patuxent River Silver Spring Washington Navy Yard

Cleveland Dahlgren Denver Johnson Space Center Montgomery New Orleans Oklahoma City San Antonio San Diego Tampa Tacoma Vandenberg AFB

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PRT-57, 21 Nov 2010

AcknowledgementsAcknowledgements

NASA JSC, Constellation Mission Operations Project funded the concept development and tool development

Terri Blatt for her support in applying the technique to the MOP PP&C environment

Greg Hay for keeping monthly revisions of the MOP schedule and providing them for use in testing the schedule comparison tool

Mike Stelly for his help with the presentation content

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OverviewOverview What is Schedule Performance?

Purpose: develop methods/techniques to analyze schedule performance over time

Development to date consists of two pieces: Performance Metrics and Toolset for analyzing data

Toolset takes two schedules and extracts appropriate data MS Project-based schedules Prototype stage of development

Batch program that created an Excel style tab-delimited text output Excel macros to format the spreadsheet for easy viewing Prototype Desktop program for immediate display and optional saving to an Excel

file

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What is Schedule Performance? and Why do we need more metrics?

What is Schedule Performance? and Why do we need more metrics?

The collection of project cost performance measures based on actual resource cost is often made difficult by inaccurate or missing resource cost data

Yet even basic schedules includes quantitative data, which can be used in measuring schedule performance. This includes: Task start and end dates Task durations Task completion assessment

The VALUE expressed in all schedules is in the TIME COST (duration) of the tasks

Using two schedules in a comparison process provides A statement of planned activity, in the earlier schedule A statement of performed activity, in the later schedule

Schedule Performance is simply “measuring a project’s ability to complete its planned activities in a given timeframe”

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Schedule Performance,Definition of Terms

Schedule Performance,Definition of Terms

Paralleling the traditional earned value approach to performance measurements we can define terms for measuring our schedule performance against the plan as follows: Planned Duration Of Work Scheduled (PDWS)

Original planned duration of activities

Planned Duration of Work Performed (PDWP) Earned duration of completed activities

Actual Duration of Work Performed (ADWP) Actual duration of completed activities

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Schedule 1

Schedule 2

Original plan is for 10 days, therefore

PDWS=10

Completed 100% of the 10 day planned activity, therefore PDWP=10

Activity took 12 days to complete, therefore

ADWP=12

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Schedule Earned ValueMetrics

Schedule Earned ValueMetrics

Based on the performance measures a number of metrics can be calculated Schedule Variance for Duration (SVd): PDWP - PDWS

The difference between earned duration and planned duration Negative values imply a schedule slip

Schedule Performance Index for Duration (SPId): PDWP/PDWS Schedule efficiency factor representing the relationship between the earned

duration and the planned duration Values less than 1.0 indicate a performance shortfall

Schedule Cost Performance Index (SCPI) : PDWP/ADWP A Schedule cost efficiency factor representing the relationship between the

earned duration and the actual duration Values less than 1.0 indicate a cost (duration) overrun

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If PDWS=10, PDWP=10, and ADWP=12, thenSchedule Variance (SVd): PDWP – PDWS = 10 - 10 = 0 - Interpretation: The scheduled task is earning value on schedule

Schedule Performance Index (SPId): PDWP/PDWS = 10 / 10 = 1.0- Interpretation: The scheduled task has earned value perfectly against its planned value

Schedule Cost Performance Index (SCPI): PDWP/ADWP = 10/12 = .833- Interpretation: The scheduled task took longer (cost more) to complete than originally planned

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Project Level Measures,A Simple Example

Project Level Measures,A Simple Example

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Schedule Variance (SVd): PDWP – PDWS = 25-30 = -5 - Interpretation: The cumulative effect of all schedule tasks analyzed are 5 days behind schedule (not to be interpreted as the overall project is 5 days behind schedule)

Schedule Performance Index (SPId): PDWP/PDWS = 25/30 = .83- Interpretation: The project has currently earned 83% of the duration that it had planned to-date

Schedule Cost Performance Index (SCPI): PDWP/ADWP = 25/32 = .78- Interpretation: Tasks are taking longer to complete than originally planned

Schedule 1

Schedule 2

Task 1PDWS: 10PDWP: 10ADWP: 12

Task 2PDWS: 10PDWP: 8ADWP: 10

Task 3PDWS: 8PDWP: 7ADWP: 8

Task 4PDWS: 2PDWP: 0ADWP: 2

Overall ProjectPDWS: 30PDWP: 25ADWP: 32

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Why Create a Schedule Comparison Tool from Scratch?

Why Create a Schedule Comparison Tool from Scratch?

There are no existing tools that create these performance measures

We were motivated to build a tool that could be used for comparing ANY two schedule instances from the same project

Performance measures can be output in a user friendly format (Excel) or directly to a database

Comparing the current schedule against the original schedule provides performance measures for the project up to the current schedule’s status date (Data Date)

Using schedules with monthly Data Date intervals will provide performance measures for that month interval

Monthly performance measures can be used for performance trending

Performance Indices can be used for duration projections and schedule confidence level analyses

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Creating aSchedule Comparison

Tool

Creating aSchedule Comparison

Tool

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Key Requirements for our Schedule Comparison ToolKey Requirements for our

Schedule Comparison Tool Use any two revisions of a project’s schedule

Create output that “aligns” the two schedules at the task level Tasks are aligned by Task Name

Create Performance Measures for each task

Create Performance Measures for the project

Retain the schedule hierarchical structure Schedules are by their nature organized in a hierarchical structure of

summary tasks and regular tasks

Create Performance Measures at each Summary task level Allows performance measures to be used to reflect the task

organization, as modeled in the schedule hierarchy (project teams?, project phases?)

Create data capable of being stored in a database

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Real World DataReal World Data

Schedule 1 Structure

Schedule 1 Task Data

Task Performance Metrics

Project Performance Indexes

Interpretation of Project Metrics• All currently analyzed tasks are cumulatively behind

schedule by 61.32 days. • Analyzed tasks have earned 92.1% of the duration they

should have earned• Tasks are being accomplished at a 65.5% efficiency rate

Schedule 2 Task Data

Summary Performance Metrics

Projected Durations using SCPI

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Current Issues & Future Development

Current Issues & Future Development

Current Issues Metrics and process

SPId tends toward 1 as task nears completion May exceed 1 if task finishes early

SPId subject to how scheduler determines “% complete” field

SCPId is used for new duration estimate SCPI (PDWP/ADWP) can be zero when task is in progress

Tool Uses task names as the identifier to compare tasks

Renamed tasks are not comparable unless new name “contains” old name Changes in schedule hierarchy makes analysis difficult

Tool option allows looking one level deeper Added tasks are ignored Deleted tasks are excluded from performance metrics

Future Development Data capture for trending analysis Extraction of task “confidence measures” (low, mode, high duration)

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ConclusionsConclusions Strengths

Does not require resource cost data for performance measures Allows ANY two revisions of a schedule to be compared Creates Task, Summary Task and Project-level performance measures Summary Task performance indices identify items needing attention

Weaknesses Relies on project percent complete measures from the schedules New (projected) duration estimation function needs refining

Conclusion Useful performance measures can be obtained from basic schedule data Performance indices are useful focusing functions Schedule comparison provides an earned value (duration) perspective

without an EVMS

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