Docstoc

The Capability Maturity Model

Document Sample
The Capability Maturity Model Powered By Docstoc
					Object-Oriented
Analysis and Design
           Lecture 9
    The Capability Maturity
            Model
Background
   Above all, this is about management, not
    technology.
   Technology promises productivity gains,
    but they will likely be unfulfilled in a
    “maelstrom of an undisciplined, chaotic
    project.”
   1986, the SEI and Mitre decide to do
    something: a process maturity framework
    to help organizations improve their
    software process.
Background (cont.)
   The methods are “software process
    assessment'' and “software capability
    evaluation.''
   Note the ideas, methods and the
    language are DoD-centric.
   Once again, “guidance.”
Background (cont.)
   The result of the SEI effort is the Capability
    Maturity Model (CMM), which is
   “...sets of recommended practices in a number
    of key process areas that have been shown to
    enhance software process capability.”
   A better mousetrap will come from a better
    mousetrap process.
The Immature Organization
   Software processes are generally improvised
    during the course of a project.
   Managers are reactionary, solving immediate
    crises.
   Functionality and quality are compromised
    when hard deadlines approach. “The death
    march to Egghead.”
   No objective basis for judging product quality;
    thus quality is difficult to predict.
The Mature Organization
   The software process is accurately
    communicated to existing and new staff.
   Work activities are actually carried out
    according to the planned process.
   The mandated processes are usable and
    consistent with the way work actually gets
    done.
   Roles and responsibilities are clear,
    schedules and budgets are based on
    historical performance.
Fundamental Concepts
   Software process: methods, activities,
    practices used to develop and maintain
    software
   Software process capability: the range of
    expected results achieved by following a
    software process.
   Software process performance: the actual
    results achieved by following a software
    process.
More Concepts
   Software process maturity: the
    extent to which a specific process is
    explicitly defined, managed, measured,
    controlled, and effective.
   As an organization gains in process
    maturity, it institutionalizes its process
    by policies, standards and organizational
    structures.
The Five Levels
   The key idea is to identify an evolutionary path
    from immature to mature.
   There are a number of well-defined plateaus
    along the way.
   Each plateau (level) is a set of process goals
    which, when satisfied, stabilize some
    component of the software process.
   The process goals are prioritized, so
    organizations understand what to do next.
The CMM Levels
Level 1: The Initial Level
   Unstable environment
   Makes commitments that can't be meet
    with an orderly process.
   Plans are scrapped during crises,
    jumping to coding and testing.
   Can success happen? Yes, but only
    through heroic efforts.
Level 1 (cont.)
   Such efforts will not likely be repeatable.
   Capability is a characteristic of
    individuals, not the organization.
   Would you buy from such an
    organization?
Level 2: The Repeatable Level
   Management policies are in place.
   Planning and managing are based on
    experience.
   Policies are enhanced on a project by
    project basis.
   Commitments are realistic.
Level 2 (cont.)
   Managers track software costs,
    schedules, functionality.
   Project standards are defined and
    followed.
   The process is disciplined because
    planning and tracking are stable.
   Earlier successes can be repeated.
Level 3: The Defined Level
   A standard process for software
    engineering and management across the
    organization is documented.
   There is a group responsible for this
    standard software process.
   There are organization-wide training
    programs.
Level 3 (cont.)
   Projects tailor the standard process to account
    for their unique features.
   Such a tailored process contains readiness
    criteria, inputs, verification mechanisms,
    outputs and completion criteria.
   This process capability is based on a common,
    organization-wide understanding of activities,
    roles and responsibilities.
Level 4: The Managed Level
   The organization sets quantitative quality goals
    for software products and processes.
   A process database is used to collect and
    analyze data from projects' processes.
   Variation in process performance is narrowed
    to acceptable levels.
   Software processes are instrumented.
Level 4 (cont.)
   Risks in new product development are
    well understood.
   The process capability is quantifiable
    and predictable.
   Software products are of predictably
    high quality.
Level 5: The Optimizing
Level

   The entire organization is focused on
    continuous process improvement.
   Weaknesses can be identified and
    remedies found.
   Data on software process allows cost-
    benefit analyses on new technologies.
Management View of
“Visibility” Into a Project
   Moving through the levels, managers
    are better informed, and have greater
    control to do good…
Management View of
“Visibility” Into a Project
   Level 1:
       The project is a black box
       Requirements flow into the project
        haphazardly
       The staging of activities is hidden
       Managers can’t establish project status
Management View of
“Visibility” Into a Project
   Level 2:
       Requirements are controlled
       Visibility at defined occasions
       The project is a sequence of black boxes
       Management reacts to problems as they
        occur
Management View of
“Visibility” Into a Project
   Level 3:
       Tasks inside each black box are known
       Management and engineers understand
        their “roles and responsibilities” within
        each box
       Management is proactive in dealing with
        problems, because of rapid status updates
Management View of
“Visibility” Into a Project
   Level 4:
       Processes are “instrumented” (details of
        estimates and outcomes are recorded)
       Decisions are based on hard facts
       Outcomes can be predicted more
        accurately
       Variability in outcomes gets smaller
Management View of
“Visibility” Into a Project
   Level 5:
       Improved methods of software
        development are regularly tried
       Defect-prone activities are replaced
       Managers can predict the impact of
        process changes
Process Capability and
Prediction of Performance

   Three improvements are expected as
    the software process matures:
       The difference between targeted results
        and actual results decreases.
       The variability of actual results around
        targeted results decreases.
       Targeted results improve as maturity
        increases.
Operational Definitions
   These are supposed to be specific
    recommendations for an organization to
    increase its maturity.
   There are at least four uses for them:
Operational Definitions (cont.)
   Assessment teams use CMM to identify
    strengths and weaknesses.
   Evaluation teams use CMM to identify risks in
    selecting contractors.
   Upper management will use CMM to figure out
    how to launch a process improvement
    program.
   Staff and process improvement groups will be
    guided by CMM.
Key Process Areas: Level 2
   Requirements management
   Software project planning
   Software project tracking and oversight
   Software subcontract management
   Software quality assurance
   Software configuration management
Key Process Areas: Level 3
   Organization process focus
   Organization process definition
   Training program
   Integrated software management
   Software product engineering
   Intergroup coordination
   Peer reviews
Key Process Areas: Level 4
   Quantitative process management
   Software quality management
Key Process Areas: Level 5
   Process change management
   Technology change management
   Defect prevention
Evaluation
   Process maturity is evaluated by SEI
    teams (and those trained by them).
   For each Key Process Area, an
    organization is rated according to:
       Commitment to perform
       Ability to perform
       Activities performed
       Measurement and analysis
       Verifying implementation
Comments From Ed Yourdon
   This is not the only model (cf. Software
    Productivity Research, the Capers Jones
    outfit)
   What about small, innovative firms?
    According to the CMM, “Apple Computer
    should not exist.”
   Small organizations probably cannot
    afford the overhead required by CMM.
Other Implications
   You can't skip levels (these are cultural
    changes).
   It takes time to go from one level to the next
    (10 years total? What about regression?).
   New technology should be avoided at lower
    levels (these are management issues).
   New software organizations won't start at level
    3 (the all-star team).
   Evaluations important for winning contracts.
A Serious Rebuttal
   From James Bach:
       “The CMM is a broad and increasingly deep
        set of assertions about good software
        development practice.”
       Where do these assertions come from?
        Are they complete and correct?
Bach (cont.)
   “My thesis...is that the CMM is a
    particular mythology about software
    process evolution that cannot
    legitimately claim to be a natural or
    essential representation of software
    processes.”
More Bach
   The CMM is
       “at best a consensus among a particular
        group of software theorists and practitioners”
       “at worst a whitewash that obscures the true
        dynamics of software engineering [and]
        suppresses alternative models”
   “If an organization follows it for its own
    sake, it may lead to the collapse of that
    company's competitive potential.”
Other Comments
   The CMM was originally designed to
    evaluate the ability of government
    contractors to develop a software project.
    Will/does it work?
   Is it useful outside of this context?
   The biggest (popularly-known) names in
    software (Borland, Symantec, Apple,
    Microsoft) are likely Level 1. (Note in Jim
    McCarthy's book, CMM isn't even
    mentioned.)
Shrink-Wrap Perspective
   No theoretical basis; fashioned by “very
    knowledgeable people,” so the de facto
    principle is that experts know what they're
    doing.
   Any other model from “very knowledgeable
    people” has equal veracity.
   Vague empirical support; this support doesn't
    exclude other models; there is no comparison
    of methods.
Shrink-Wrap (cont.)
   It doesn't account for the success of
    shrink-wrap companies.
   CMM reveres process but ignores
    people; process makes up for
    mediocrity; where is the justification for
    this?
Shrink-Wrap (cont.)
   Imagine a process definition for playing chess.
   Institutionalization of process guarantees
    nothing; such efforts lead to a simplified public
    process and an undercover private process.
   Process dynamics are lost; why isn't training at
    level 1, for example? Level 1 is nothing; just
    get to level 2!
Shrink-Wrap (cont.)
   Most of the Key Practices could be
    introduced at level 1, depending on the
    organization.
   The CMM replaces the true mission of
    better process to the artificial mission of
    higher maturity level; “level envy.”
Other Arguments
   The most powerful argument against
    CMM is the many successful companies
    that should not exist. Microsoft is level
    1, IBM is mature.
   Process should support innovation;
    systematic problem-solving leadership to
    enable innovation rather than cookie-
    cutter solutions.
Still More
   CMM is profoundly ignorant of the dynamics of
    innovation. CMM pushes authority up in the
    organization.
   For CMM, heroism is an unsustainable sacrifice
    on the part of individuals. Personal mastery is
    left out of the equation.
   An alternative: well, Bach obviously has his
    own story...

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:19
posted:11/16/2012
language:English
pages:47