Post on 24-Dec-2015
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
10
15
20
25
30
35
40
45
50
06/01
/06
13/01
/06
20/01
/06
27/01
/06
03/02
/06
10/02
/06
17/02
/06
24/02
/06
Sto
ry P
oin
ts
Individuals and Moving Range (XmR) ChartsIndividuals and Moving Range (XmR) Charts
Velocity
0
10
20
30
40
50
60
06/0
1/20
06
13/0
1/20
06
20/0
1/20
06
27/0
1/20
06
03/0
2/20
06
10/0
2/20
06
17/0
2/20
06
24/0
2/20
06
weeks
sto
ry p
oin
ts
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
10
20
30
40
50
60
06/0
1/20
06
13/0
1/20
06
20/0
1/20
06
27/0
1/20
06
03/0
2/20
06
10/0
2/20
06
17/0
2/20
06
24/0
2/20
06
weeks
sto
ry p
oin
ts
story points
LNPLX
UNPLX
‘Burn-down’‘Burn-down’
Story Points Remaing
0
50
100
150
200
250
300
350
06/0
1/20
06
13/0
1/20
06
20/0
1/20
06
27/0
1/20
06
03/0
2/20
06
10/0
2/20
06
17/0
2/20
06
24/0
2/20
06
Sto
ry P
oin
ts
With the appropriate metrics we can improveWith the appropriate metrics we can improve
Acceptance Test Data
0
10
20
30
40
50
60
70
80
90
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