UNIT-III

Work Flows of the process: Software process workflows, Iteration workflows.

Checkpoints of the process: Major mile stones, Minor Milestones, Periodic status assessments.
Iterative Process Planning: Work breakdown structures, planning guidelines, cost and schedule
estimating, Iteration planning process, Pragmatic planning.
WORKFLOW OF THE PROCESS
SOFTWARE PROCESS WORKFLOWS
The term WORKFLOWS is used to mean a thread of cohesive and mostly sequential activities.
Workflows are mapped to product artifacts There are seven top-level workflows:
1. Management workflow: controlling the process and ensuring win conditions for all stakeholders
2. Environment workflow: automating the process and evolving the maintenance environment
3. Requirements workflow: analyzing the problem space and evolving the requirements artifacts
4. Design workflow: modeling the solution and evolving the architecture and design artifacts
5. Implementation workflow: programming the components and evolving the implementation and
deployment artifacts
6. Assessment workflow: assessing the trends in process and product quality
7. Deployment workflow: transitioning the end products to the user
Figure 8-1 illustrates the relative levels of effort expected across the phases in each of the top-level
workflows

Table 8-1 shows the allocation of artifacts and the emphasis of each workflow in each of the life-
cycle phases of inception, elaboration, construction, and transition.
 ITERATION WORKFLOWS
Iteration consists of a loosely sequential set of activities in various proportions, depending on where
the iteration is located in the development cycle. Each iteration is defined in terms of a set of
allocated usage scenarios. An individual iteration's workflow, illustrated in Figure 8-2, generally
includes the following sequence:
 Management: iteration planning to determine the content of the release and develop the detailed
plan for the iteration; assignment of work packages, or tasks, to the development team
 Environment: evolving the software change order database to reflect all new baselines and changes
to existing baselines for all product, test, and environment components

Requirements: analyzing the baseline plan, the baseline architecture, and the baseline requirements
set artifacts to fully elaborate the use cases to be demonstrated at the end of this iteration and their
evaluation criteria; updating any requirements set artifacts to reflect changes necessitated by results
of this iteration's engineering activities
 Design: evolving the baseline architecture and the baseline design set artifacts to elaborate fully the
design model and test model components necessary to demonstrate against the evaluation criteria
allocated to this iteration; updating design set artifacts to reflect changes necessitated by the results
of this iteration's engineering activities
 Implementation: developing or acquiring any new components, and enhancing or modifying any
existing components, to demonstrate the evaluation criteria allocated to this iteration; integrating
 and testing all new and modified components with existing baselines (previous versions)
 Assessment: evaluating the results of the iteration, including compliance with the allocated
evaluation criteria and the quality of the current baselines; identifying any rework required and
determining whether it should be performed before deployment of this release or allocated to the
next release; assessing results to improve the basis of the subsequent iteration's plan
 Deployment: transitioning the release either to an external organization (such as a user,
independent verification and validation contractor, or regulatory agency) or to internal closure by
conducting a post-mortem so that lessons learned can be captured and reflected in the next iteration
Iterations in the inception and elaboration phases focus on management. Requirements, and design
activities. Iterations in the construction phase focus on design, implementation, and assessment.
Iterations in the transition phase focus on assessment and deployment. Figure 8-3 shows the
emphasis on different activities across the life cycle. An iteration represents the state of the overall
architecture and the complete deliverable system. An increment represents the current progress that
will be combined with the preceding iteration to from the next iteration. Figure 8-4, an example of a
simple development life cycle, illustrates the differences between iterations and increments.
CHECK POINTS OF THE PROCESS
 Checkpoints of the process
Three types of joint management reviews are conducted throughout the process:
1. Major milestones. These system wide events are held at the end of each development phase.
They provide visibility to system wide issues, synchronize the management and engineering
perspectives, and verify that the aims of the phase have been achieved.
2. Minor milestones. These iteration-focused events are conducted to review the content of an
iteration in detail and to authorize continued work.
3. Status assessments. These periodic events provide management with frequent and regular
insight into the progress being made.
Each of the four phases-inception, elaboration, construction, and transition consists of one or more
iterations and concludes with a major milestone when a planned technical capability is produced in
demonstrable form. An iteration represents a cycle of activities for which there is a well-defined
intermediate result-a minor milestone-captured with two artifacts: a release specification (the
evaluation criteria and plan) and a release description (the results). Major milestones at the end of
each phase use formal, stakeholder-approved evaluation criteria and release descriptions; minor
milestones use informal, development-team-controlled versions of these artifacts.
Figure 9-1 illustrates a typical sequence of project checkpoints for a relatively large project.

MAJOR MILESTONES
The four major milestones occur at the transition points between life-cycle phases. They can be used in many different
process models, including the conventional waterfall model. In an iterative model, the major milestones are used to
achieve concurrence among all stakeholders on the current state of the project. Different stakeholders have very
different concerns:
 Customers: schedule and budget estimates, feasibility, risk assessment, requirements
understanding, progress, product line compatibility
 Users: consistency with requirements and usage scenarios, potential for accommodating growth,
quality attributes
 Architects and systems engineers: product line compatibility, requirements changes, trade-off
analyses, completeness and consistency, balance among risk, quality, and usability
 Developers: sufficiency of requirements detail and usage scenario descriptions, . frameworks for
component selection or development, resolution of development risk, product line compatibility,
sufficiency of the development environment
 Maintainers: sufficiency of product and documentation artifacts, understandability, interoperability
with existing systems, sufficiency of maintenance environment
 Others: possibly many other perspectives by stakeholders such as regulatory agencies, independent
verification and validation contractors, venture capital investors, subcontractors, associate
contractors, and sales and marketing teams
Table 9-1 summarizes the balance of information across the major milestones.

Life-Cycle Objectives Milestone

The life-cycle objectives milestone occurs at the end of the inception phase. The goal is to present
to all stakeholders a recommendation on how to proceed with development, including a plan,
estimated cost and schedule, and expected benefits and cost savings. A successfully completed life-
cycle objectives milestone will result in authorization from all stakeholders to proceed with the
elaboration phase.
Life-Cycle Architecture Milestone
The life-cycle architecture milestone occurs at the end of the elaboration phase. The primary goal is
to demonstrate an executable architecture to all stakeholders. The baseline architecture consists of
both a human- readable representation (the architecture document) and a configuration-controlled
set of software components captured in the engineering artifacts. A successfully completed life-
cycle architecture milestone will result in authorization from the stakeholders to proceed with the
construction phase.
The technical data listed in Figure 9-2 should have been reviewed by the time of the lifecycle

architecture milestone. Figure 9-3 provides default agendas for this milestone.
 Initial Operational Capability Milestone
The initial operational capability milestone occurs late in the construction phase. The goals are to
assess the readiness of the software to begin the transition into customer/user sites and to authorize
the start of acceptance testing. Acceptance testing can be done incrementally across multiple
iterations or can be completed entirely during the transition phase is not necessarily the completion
of the construction phase.
Product Release Milestone
The product release milestone occurs at the end of the transition phase. The goal is to assess the
completion of the software and its transition to the support organization, if any. The results of
acceptance testing are reviewed, and all open issues are addressed. Software quality metrics are
reviewed to determine whether quality is sufficient for transition to the support organization.

MINORMILESTONES
For most iterations, which have a one-month to six-month duration, only two minor milestones are
needed: the iteration readiness review and the iteration assessment review.
 Iteration Readiness Review. This informal milestone is conducted at the start of each iteration to
review the detailed iteration plan and the evaluation criteria that have been allocated to this iteration
.
 Iteration Assessment Review. This informal milestone is conducted at the end of each iteration to
assess the degree to which the iteration achieved its objectives and satisfied its evaluation criteria,
to review iteration results, to review qualification test results (if part of the iteration), to determine
the amount of rework to be done, and to review the impact of the iteration results on the plan for
subsequent iterations.

The format and content of these minor miles tones tend to be highly dependent on the project and
the organizational culture. Figure 9-4 identifies the various minor milestones to be considered when
a project is being planned.

PERIODIC STATUS ASSESSMENTS

Periodic status assessments are management reviews conducted at regular intervals (monthly, quarterly) to
address progress and quality indicators, ensure continuous attention to project dynamics, and maintain open
communications among all stakeholders.
Periodic status assessments serve as project snapshots. While the period may vary, the recurring event forces
the project history to be captured and documented. Status assessments provide the following:
 A mechanism for openly addressing, communicating, and resolving management issues, technical issues, and
 project risks
 Objective data derived directly from on-going activities and evolving product configurations
 A mechanism for disseminating process, progress, quality trends, practices, and experience information to and
from all stakeholders in an open forum
Periodic status assessments are crucial for focusing continuous attention on the evolving health of the project
and its dynamic priorities. They force the software project manager to collect and review the data periodically,
force outside peer review, and encourage dissemination of best practices to and from other stakeholders.
The default content of periodic status assessments should include the topics identified in Table 9-2.

ITERATIVE PROCESS PLANNING

A good work breakdown structure and its synchronization with the process framework are critical
factors in software project success. Development of a work breakdown structure dependent on the
project management style, organizational culture, customer preference, financial constraints, and
several other hard-to-define, project-specific parameters.
A WBS is simply a hierarchy of elements that decomposes the project plan into the discrete work
tasks. A WBS provides the following information structure:
 A delineation of all significant work
 A clear task decomposition for assignment of responsibilities
 A framework for scheduling, budgeting, and expenditure tracking
Many parameters can drive the decomposition of work into discrete tasks: product subsystems,
components, functions, organizational units, life-cycle phases, even geographies. Most systems
have a first-level decomposition by subsystem. Subsystems are then decomposed into their
components, one of which is typically the software.
 CONVENTIONALWBSISSUES
Conventional work breakdown structures frequently suffer from three fundamental flaws.
1. They are prematurely structured around the product design.
2. They are prematurely decomposed, planned, and budgeted in either too much or too little detail.
3. They are project-specific, and cross-project comparisons are usually difficult or impossible.
Conventional work breakdown structures are prematurely structured around the product design.
Figure 10-1 shows a typical conventional WBS that has been structured primarily around the
subsystems of its product architecture, then further decomposed into the components of each
subsystem. A WBS is the architecture for the financial plan.
Conventional work breakdown structures are prematurely decomposed, planned, and budgeted in
either too little or too much detail. Large software projects tend to be over planned and small
projects tend to be under planned. The basic problem with planning too much detail at the outset is
that the detail does not evolve with the level of fidelity in the plan.
Conventional work breakdown structures are project-specific, and cross-project comparisons are
usually difficult or impossible. With no standard WBS structure, it is extremely difficult to compare
plans, financial data, schedule data, organizational efficiencies, cost trends, productivity trends, or
quality trends across multiple projects.

Figure10-1Conventionalworkbreakdownstructure,followingtheproducthierarchy

Management
Systemrequirementanddesign Subsystem 1
Component 11 Requirements Design
Code Test
Documentation
…(similarstructuresforothercomponents)
Component 1N Requirements Design
Code Test
Documentation
…(similarstructuresforother subsystems)
Subsystem M ComponentM1
Requirements Design
Code Test
Documentation
…(similarstructuresforothercomponents) Component MN
Requirements Design
Code Test
Documentation Integration and test
Testplanning
Testprocedurepreparation Testing
Test reports Othersupportareas
Configuration control Quality assurance Systemadministration

EVOLUTIONARYWORKBREAKDOWNSTRUCTURES
An evolutionary WBS should organize the planning elements around the process framework rather
than the product framework. The basic recommendation for the WBS is to organize the hierarchy as
follows:
 First-level WBS elements are the workflows (management, environment, requirements, design,
implementation, assessment, and deployment).
 Second-level elements are defined for each phase of the life cycle (inception, elaboration,
construction, and transition).
 Third-level elements are defined for the focus of activities that produce the artifacts of each
phase.
A default WBS consistent with the process framework (phases, workflows, and artifacts) is shown
 in Figure 10-2. This recommended structure provides one example of how the elements of the
process framework can be integrated into a plan. It provides a framework for estimating the costs
and schedules of each element, allocating them across a project organization, and tracking
expenditures.
The structure shown is intended to be merely a starting point. It needs to be tailored to the specifics
of a project in many ways.
 Scale. Larger projects will have more levels and substructures.
 Organizational structure. Projects that include subcontractors or span multiple organizational
entities may introduce constraints that necessitate different WBS allocations.
 Degree of custom development. Depending on the character of the project, there can be very
different emphases in the requirements, design, and implementation workflows.
 Business context. Projects developing commercial products for delivery to a broad customer base
 may require much more elaborate substructures for the deployment element.
 Precedent experience. Very few projects start with a clean slate. Most of them are developed as new
generations of a legacy system (with a mature WBS) or in the context of existing organizational
standards (with preordained WBS expectations).
The WBS decomposes the character of the project and maps it to the life cycle, the budget, and the
personnel. Reviewing a WBS provides insight into the important attributes, priorities, and structure
of the project plan.
Another important attribute of a good WBS is that the planning fidelity inherent in each element is
commensurate with the current life-cycle phase and project state. Figure 10-3 illustrates this idea.
One of the primary reasons for organizing the default WBS the way I have is to allow for planning
elements that range from planning packages (rough budgets that are maintained as an estimate for
future elaboration rather than being decomposed into detail) through fully planned activity networks
(with a well-defined budget and continuous assessment of actual versus planned expenditures).
Figure10-2Defaultworkbreakdownstructure
A Management
AA Inception phase management
AAA Business case development
AAB Elaboration phase release specifications
AAC Elaboration phase WBS specifications
AAD Software development plan
AAE Inception phase project control and status assessments
AB Elaboration phase management
ABA Construction phase release specifications
ABB Construction phase WBS baselining
ABC Elaboration phase project control and status assessments
AC Construction phase management
ACA Deployment phase planning
ACB Deployment phase WBS baselining
ACC Construction phase project control and status assessments
AD Transition phase management
ADA Next generation planning
ADB Transition phase project control and status assessments
B Environment
BA Inception phase environment specification
BB Elaboration phase environment baselining
BBA Development environment installation and administration
BBB Development environment integration and custom tools mithing
BBC SCO database formulation
BC Construction phase environment maintenance
BCA Development environment installation and administration
BCB SCO database maintenance
BD Transition phase environment maintenance
BDA Development environment maintenance and administration
BDB SCO database maintenance
BDC Maintenance environment packaging and transition
C Requirements
CA Inception phase requirements development
CCA Vision specification
CAB Use case modeling
CB Elaboration phase requirements baselining
CBA Vision baselining
CBB Use case model baselining
CC Construction phase requirements maintenance
CD Transition phase requirements maintenance
D Design
DA Inception phase architecture prototyping
DB Elaboration phase architecture baselining
DBA Architecture design modeling
 DBB Design demonstration planning and conduct
DBC Software architecture description
DC Construction phase design modeling
DCA Architecture design model maintenance
DCB Component design modeling
DD Transition phase design maintenance
E Implementation
EA Inception phase component prototyping
EB Elaboration phase component implementation
EBA Critical component coding demonstration integration
EC Construction phase component implementation
ECA Initial release(s) component coding and stand-alone testing
ECB Alpha release component coding and stand-alone testing
ECC Beta release component coding and stand-alone testing
ECD Component maintenance
F Assessment
FA Inception phase assessment
FB Elaboration phase assessment
FBA Test modeling
FBB Architecture test scenario implementation
FBC Demonstration assessment and release descriptions
FC Construction phase assessment
FCA Initial release assessment and release description
FCB Alpha release assessment and release description
FCC Beta release assessment and release description
FD Transition phase assessment
FDA Product release assessment and release description
G Deployment
GA Inception phase deployment planning
GB Elaboration phase deployment planning
GC Construction phase deployment
GCA User manual baselining
GD Transition phase deployment
GDA Product transition to user
 PLANNING GUIDELINES
Software projects span a broad range of application domains. It is valuable but risky to make
specific planning recommendations independent of project context. Project-independent planning
advice is also risky. There is the risk that the guidelines may pe adopted blindly without being
adapted to specific project circumstances. Two simple planning guidelines should be considered
when a project plan is being initiated or assessed. The first guideline, detailed in Table 10-1,
prescribes a default allocation of costs among the first-level WBS elements. The second guideline,
detailed in Table 10-2, prescribes the allocation of effort and schedule across the lifecycle phases.
10-1Webbudgetingdefaults
First Level WBS Default
Element Budget
Management 10%
Environment 10%
Requirement 10%
Design 15%
Implementation 25%
Assessment 25%
Deployment 5%
Total 100%

Table10-2Defaultdistributionsofeffortandscheduleby phase
Do Inc Elab Const Tra
ma epti orati ructio nsit
in on on n ion
Eff 5% 20% 65% 10
ort %
Sc 10 30% 50% 10
he % %
dul
e
THECOSTANDSCHEDULEESTIMATINGPROCESS
Project plans need to be derived from two perspectives. The first is a forward-looking, top- down
approach. It starts with an understanding of the general requirements and constraints, derives a
macro-level budget and schedule, then decomposes these elements into lower level budgets and
intermediate milestones. From this perspective, the following planning sequence would occur:

1. The software project manager (and others) develops a characterization of the overall size, process,
environment, people, and quality required for the project.
2. A macro-level estimate of the total effort and schedule is developed using a software cost
estimation model.
3. The software project manager partitions the estimate for the effort into a top-level WBS using
guidelines such as those in Table 10-1.
4. At this point, subproject managers are given the responsibility for decomposing each of the WBS
elements into lower levels using their top-level allocation, staffing profile, and major milestone
dates as constraints.
Thesecondperspectiveisabackward-looking,bottom-upapproach.Westartwiththeendin mind, analyze
the micro-level budgets and schedules, then sum all these elements into the higher level budgets and
intermediate milestones. This approach tends to define and populate the WBS from the lowest
levels upward. From this perspective, the following planning sequence would occur:
1. The lowest level WBS elements are elaborated into detailed tasks
2. Estimates are combined and integrated into higher level budgets and milestones.
3. Comparisons are made with the top-down budgets and schedule milestones.
Milestone scheduling or budget allocation through top-down estimating tends to exaggerate the
project management biases and usually results in an overly optimistic plan. Bottom-up estimates
usually exaggerate the performer biases and result in an overly pessimistic plan.
These two planning approaches should be used together, in balance, throughout the life cycle of the
project. During the engineering stage, the top-down perspective will dominate because there is
usually not enough depth of understanding nor stability in the detailed task sequences to perform
credible bottom-up planning. During the production stage, there should be enough precedent
experience and planning fidelity that the bottom-up planning perspective will dominate. Top-down
approach should be well tuned to the project-specific parameters, so it should be used more as a
global assessment technique. Figure 10-4 illustrates this life- cycle planning balance.

THE ITERATION PLANNING PROCESS

Planning is concerned with defining the actual sequence of intermediate results. An evolutionary
build plan is important because there are always adjustments in build content and schedule as early
 conjecture evolves into well-understood project circumstances. Iteration is used to mean a complete
synchronization across the project, with a well-orchestrated global assessment of the entire project
baseline.
 Inception iterations. The early prototyping activities integrate the foundation components of a
candidate architecture and provide an executable framework for elaborating the critical use cases of
the system. This framework includes existing components, commercial components, and custom
prototypes sufficient to demonstrate a candidate architecture and sufficient requirements
understanding to establish a credible business case, vision, and software development plan.

 Elaboration iterations. These iterations result in architecture, including a complete framework and
infrastructure for execution. Upon completion of the architecture iteration, a few critical use cases
should be demonstrable: (1) initializing the architecture, (2) injecting a scenario to drive the worst-case data
processing flow through the system (for example, the peak transaction throughput or peak load scenario),
and (3) injecting a scenario to drive the worst-case control flow through the system (for example,
orchestrating the fault-tolerance use cases).

 Construction iterations. Most projects require at least two major construction iterations: an alpha release and
a beta release.

 Transition iterations. Most projects use a single iteration to transition a beta release into the final product.The
general guideline is that most projects will use between four and nine iterations. The typical project would
have the following six-iteration profile:

1. One iteration in inception: an architecture prototype

2. Two iterations in elaboration: architecture prototype and architecture baseline
3. Two iterations in construction: alpha and beta releases
4. One iteration in transition: product release

A very large or unprecedented project with many stakeholders may require additional inception
iteration and two additional iterations in construction, for a total of nine iterations.

PRAGMATIC PLANNING
Even though good planning is more dynamic in an iterative process, doing it accurately is
far easier. While executing iteration N of any phase, the software project manager must be
monitoring and controlling against a plan that was initiated in iteration N - 1 and must be planning
iteration N + 1. The art of good project management is to make trade-offs in the current iteration
plan and the next iteration plan based on objective results in the current iteration and previous
iterations. Aside from bad architectures and misunderstood requirements, inadequate planning (and
subsequent bad management) is one of the most common reasons for project failures. Conversely,
the success of every successful project can be attributed in part to good planning.
A project's plan is a definition of how the project requirements will be transformed into' a
product within the business constraints. It must be realistic, it must be current, it must be a team
product, it must be understood by the stakeholders, and it must be used. Plans are not just for
managers. The more open and visible the planning process and results, the more ownership there is
among the team members who need to execute it. Bad, closely held plans cause attrition. Good,
open plans can shape cultures and encourage teamwork.