COMP3001 Technology Management & Professional Issues:

Project Management

Metrics

appropriate for iterative projectsLecture 6

Graham Collins, UCL

graham.collins@ucl.ac.uk

Development Metrics (measurements)Development Metrics (measurements)

Measurements have traditionally included lines of code (LOC) and there are several models based on this including the hierarchy of cost and effort models COCOMO (COnstructive COst MOdel) developed by Boehm

More recently other metrics have been used such as function points, which give a better indication of size and complexity

Recent development work (Bittner and Spence) indicates that a move to working software is perhaps one of the best measures of progress.

What is iterative development? Part 3: The management perspective 15 May 2005

www-128.ibm.com/developerworks/rational/library/may05/bittner-spence/index.html

Iterative projectsIterative projects

From the project managers perspective iterative projects can be viewed as a series of self contained projects with the application of all the disciplines of software development (requirement, analysis, design, implementation, and testing) to produce a release of the project

With the Unified Process initial iterations may establish design including architecture. With agile methods emphasis is placed on releases of working software

Bittner and Spence outline this at its simplest as series of stages.

Earned Value compared to Agile Process PlanningEarned Value compared to Agile Process Planning

Based on predictive planning

Reliable estimates effort, cost and completion date

End-to-end value tracking

Adaptive planning.

Iteration to iteration tracking

Predication of the next iterations effort

It is possible to schedule most of the activities

Adaptation to unpredictable events is problematic. Changes may require the planned to be revised or baselined

Near the beginning, it is not always possible to schedule.

Time based iterations allow initial estimate of duration which can be revised through the adaptive driven build-feedback cycle

Estimates based on past performance Estimates are based on progress being made (velocity)

Change rates often low Unpredictable change the norm

Small variations in early measurements of cost and time at the start the project give wide variation in forward predications

Unknown team development rates

Some organisations do not chart progress for an initial period

Progress is tracked immediately

Earned value well established Prioritization of the value of user stories

No earned value approaches in methods

Earned Value Agile Development

CMMI Comparative AdvantagesCMMI Comparative Advantages

Grants explicit freedom to select the order of improvement that best meets the organization’s business objectives and mitigates the organisation’s areas of risk

Enables organisations to have a predefined path

Enables increased visibility of the capability achieved in each individual process area

Focuses on a set of processes that provide an organization with a specific capability that is characterized by each maturity level

Provides a capability-level rating that is used primarily for improvement in an organisation and is rarely communicated externally

Provides a maturity-level rating that is often used in internal management communication, statements external to the organization, and during acquisitions as a means to qualify bidders

Allows improvements of different processes to be performed at different rates

Summarizes process-improvement results in a simple form – a single maturity-level number

Reflects a newer approach that does not yet have the data to demonstrate its ties to return on investment

Builds on a relatively long history of use that includes case studies and data that demonstrate proved return on investment

Continuous Representation Staged Representation

Agile ManifestoAgile Manifesto

Individuals and interactions over processes and tools

Working software over comprehensive documentation

Customer collaboration over contract negotiation

Responding to change over following a plan

That is, while there is value in the items on the right, we value the items on the left more

Several agile projects have achieved CMMI level 3, example David Anderson, Stretching Agile to fit CMMI Level 3, Agile Conference 2005

The Agile Principles www.agilealliance.comThe Agile Principles www.agilealliance.com

Our highest priority is to satisfy the customer through early and continuous delivery of valuable software

Agile processes promote sustainable development

Welcome changing requirements, even late in development. Agile processes harness change for the customer competitive advantage

The sponsors, developer, and users should be able to maintain a constant pace indefinitely

Deliver working software frequently, from a couple of weeks to a couple of months, with a preference to the shorter time scale

Continuous attention to technical excellence and good design enhances agility

Business people and developers must work together daily throughout the project

Simplicity - the art of maximizing the amount of work done – is essential

Build projects around motivated individuals. Give them the environment and support they need, and trust them to get the job done.

The best architectures, requirements, and designs emerge from self-organizing teams

The most efficient and effective method of conveying information to and within a development team is face-to-face conversation

At regular intervals the team reflects on how to become more effective, then tunes and adjusts its behaviour accordingly

Working software is the primary measure of progress

Iterative Development (Bittner-Spence)Iterative Development (Bittner-Spence)

1. Agree with the team the objectives for the iteration, including evaluation criteria, timescales, and constraints

2. Agree on a plan for how the team will achieve the objectives

3. Execute the plan

4. Assess the achievements of the team against the initial set of objectives and evaluation criteria

5. Assess the impact of the iteration’s results on the project as a whole

6. Start the next iteration.

What is iterative development? Part 3: The management perspective 15 May 2005www-128.ibm.com/developerworks/rational/library/may05/bittner-spence/index.html

Fundamental shift in measurementFundamental shift in measurement

Progress ( % complete measured in scenarios

100%

0%

Iteration 1 2 3 4

coded tested Tested & Passed

Developer PerspectiveDeveloper Perspective

Developers are less interested in the business value, benefits realization and return on investment

They work on a small number of requirements or change requests from their list of outstanding work

They anticipate a decreasing number of requirements and change requests as the product is developed

Outstanding requirements and change requests is termed the product backlog

The developer will therefore be aware of progress via work completed, product backlog and new work allocated.

User Satisfaction driving DevelopmentUser Satisfaction driving Development

User satisfaction

Iteration

ReleaseUser satisfaction

Release planning

Development IncrementIteration planning

Iteration Planning (Goal identification, story selection, tasks, estimation, team commitment)

To develop members’ capabilities; to build and exchange knowledge

Passion, commitment, and identification with the group’s expertise

To accomplish a specified task

The project’s milestones and goals

Adapted from: Communities of Practice: The organizational Frontier, Etienne C. Wenger and William M. Snyder, Harvard Business Review p139-145 Jan-Feb 2000

What is the purpose? What holds it together?

Community of practice

Project team

Project teams need to adopt some attributesProject teams need to adopt some attributes

Rate of work - velocityRate of work - velocity

Velocity

0

5

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06/01

/06

13/01

/06

20/01

/06

27/01

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/06

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/06

17/02

/06

24/02

/06

Sto

ry P

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Individuals and Moving Range (XmR) ChartsIndividuals and Moving Range (XmR) Charts

Velocity

0

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06/0

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story points mR

UCLR

UNPLx

Control Limits for XmR ChartsControl Limits for XmR Charts

k sequential measurements provide k-1 =r (two-point) moving range valuesith moving range = mRi = │Xi+1 – X i │where integer i is 1 ≤ i ≤ k - 1

___ i=r

Individuals average moving range =mR = 1 ∑ mRi r i=1

_ ___ _ ___Upper Natural Process Limit =UNPLx= X + 3mR = X + 2.660mR

d2 _ i=k

Centerline = CLx = X = 1 ∑ Xi (average of individual values) k i=1

_ ___ _ ___Lower Natural Process Limit =LNPLx= X - 3mR = X - 2.660mR

d2 ___

Centerline or average moving range = CLR = mR ___ ___

Upper Control Limit for moving range =UCLR= D4mR = 3.268mR ___

Sigma for individual values = sigmax (σ) = mR d2When n=2 d2 =1.128and D4 =3.268 (from Dispersion and Bias factor tables)

‘Under Control’‘Under Control’

Velocity measures of work rate are useful in that estimates of the next iteration can be planned in a rolling processThe use of σ variation is supportive in this aim Automated colour coding (Red Amber Green) can be used to show condition requirements

Velocity

0

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story points

LNPLX

UNPLX

‘Burn-down’‘Burn-down’

Story Points Remaing

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With the appropriate metrics we can improveWith the appropriate metrics we can improve

Acceptance Test Data

0

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100

1 2 3 4 5 6 7 8 9 10 11 12

Iteration

AT

s

Failing Ats

Passing Ts

Acceptance Tests

Use of MultipliersUse of Multipliers

Iterations Completed

Low Multiplier High Multiplier

1 0.6 1.60

2 0.8 1.25

3 0.85 1.15

4 or more 0.90 1.10

Multipliers for estimating velocity based on number of iterations completed from Cohn 2006

Charts and MetricsCharts and Metrics

Velocity and Burn-down Cumulative acceptance tests

Inventory

Failing

Passing

Cumulative Issue ChartsBacklog - Active issues (which show inventory line)

Resolved issues

Closed issues

Earned Value EV progress charts

Performance via cpi and spi

Cpi and spi combined with control charts

Earned ValueEarned Value

EV can be applied to estimates of agile projects

- this is complex if more stories are added as the work progresses

EV may need to be shown to senior managers

- who are used to EV figures, or comparison to other projects where EV figures have been tracked

EV estimates can be accurate

- story points tend to remain static in an iteration when the process is understood by managers and developers. When additional stories are added, stories with lower business priority level may be dropped to compensate and keep the work load (story points) similar.

Business ValueBusiness ValueMore importantly business value (or contribution) should be considered and evaluated

Often units of measure such as story points can be valued as 0.5 or 1.0 units

The key issue in agile project management is to continually assess with the client the most important work that should be done.

Story number

‘Business Value’

Story Points

‘Points earned’

Planned (developer hours)

Actual(logged hours)

EV (earned value)

1 3 10 10 100 120 100

2 2 8 8 60 60 60

3 2 4 4 60 80 60

4 1 2 0 20 0 0

total 8 24 22 240 260 220

Further readingFurther reading

Agile Estimating and Planning, Mike Cohn, Prentice Hall (Pearson Education) 2006 ISBN: 0-13-1479041-5

Managing Agile Projects, Sanjiv Augustine, Prentice Hall (Pearson Education) 2005 ISBN: 0-13-124071-4