Monday, July 7, 2008

Verification Strategies

What is ‘Verification’?
Verification is the process of evaluating a system or component to determine whether the products of a given development phase satisfy the conditions imposed at the start of that phase.

What is the importance of the Verification Phase?
Verification process helps in detecting defects early, and preventing their leakage downstream. Thus, the higher cost of later detection and rework is eliminated.

1. Review
A process or meeting during which a work product, or set of work products, is presented to project personnel, managers, users, customers, or other interested parties for comment or approval.
The main goal of reviews is to find defects. Reviews are a good compliment to testing to help assure quality. A few purposes’ of SQA reviews can be as follows:
• Assure the quality of deliverable before the project moves to the next stage.
• Once a deliverable has been reviewed, revised as required, and approved, it can be used as a basis for the next stage in the life cycle.
What are the various types of reviews?
Types of reviews include Management Reviews, Technical Reviews, Inspections, Walkthroughs and Audits.

Management Reviews
Management reviews are performed by those directly responsible for the system in order to monitor progress, determine status of plans and schedules, confirm requirements and their system allocation.
Therefore the main objectives of Management Reviews can be categorized as follows:
• Validate from a management perspective that the project is making progress according to the project plan.
• Ensure that deliverables are ready for management approvals.
• Resolve issues that require management’s attention.
• Identify any project bottlenecks.
• Keeping project in Control.
Support decisions made during such reviews include Corrective actions, Changes in the allocation of resources or changes to the scope of the project
In management reviews the following Software products are reviewed:
Audit Reports
Contingency plans
Installation plans
Risk management plans
Software Q/A
The participants of the review play the roles of Decision-Maker, Review Leader, Recorder, Management Staff, and Technical Staff.

Technical Reviews
Technical reviews confirm that product Conforms to specifications, adheres to regulations, standards, guidelines, plans, changes are properly implemented, changes affect only those system areas identified by the change specification.

The main objectives of Technical Reviews can be categorized as follows:
• Ensure that the software confirms to the organization standards.
• Ensure that any changes in the development procedures (design, coding, testing) are implemented per the organization pre-defined standards.
In technical reviews, the following Software products are reviewed
• Software requirements specification
• Software design description
• Software test documentation
• Software user documentation
• Installation procedure
• Release notes

The participants of the review play the roles of Decision-maker, Review leader, Recorder, Technical staff.

What is Requirement Review?

A process or meeting during which the requirements for a system, hardware item, or software item are presented to project personnel, managers, users, customers, or other interested parties for comment or approval. Types include system requirements review, software requirements review.
Who is involved in Requirement Review?
• Product management leads Requirement Review. Members from every affected department participates in the review

Input Criteria
Software requirement specification is the essential document for the review. A checklist can be used for the review.

Exit Criteria

Exit criteria include the filled & completed checklist with the reviewers’ comments & suggestions and the re-verification whether they are incorporated in the documents.

What is Design Review?
A process or meeting during which a system, hardware, or software design is presented to project personnel, managers, users, customers, or other interested parties for comment or approval. Types include critical design review, preliminary design review, and system design review.

Who involve in Design Review?

• QA team member leads design review. Members from development team and QA team participate in the review.

Input Criteria
Design document is the essential document for the review. A checklist can be used for the review.

Exit Criteria

Exit criteria include the filled & completed checklist with the reviewers’ comments & suggestions and the re-verification whether they are incorporated in the documents.


What is Code Review?
A meeting at which software code is presented to project personnel, managers, users, customers, or other interested parties for comment or approval.

Who is involved in Code Review?
• QA team member (In case the QA Team is only involved in Black Box Testing, then the Development team lead chairs the review team) leads code review. Members from development team and QA team participate in the review.

Input Criteria

The Coding Standards Document and the Source file are the essential documents for the review. A checklist can be used for the review.

Exit Criteria

Exit criteria include the filled & completed checklist with the reviewers’ comments & suggestions and the re-verification whether they are incorporated in the documents.

2. Walkthrough
A static analysis technique in which a designer or programmer leads members of the development team and other interested parties through a segment of documentation or code, and the participants ask questions and make comments about possible errors, violation of development standards, and other problems.
The objectives of Walkthrough can be summarized as follows:
• Detect errors early.
• Ensure (re)established standards are followed:
• Train and exchange technical information among project teams which participate in the walkthrough.
• Increase the quality of the project, thereby improving morale of the team members.
The participants in Walkthroughs assume one or more of the following roles:
a) Walk-through leader
b) Recorder
c) Author
d) Team member
To consider a review as a systematic walk-through, a team of at least two members shall be assembled. Roles may be shared among the team members. The walk-through leader or the author may serve as the recorder. The walk-through leader may be the author.
Individuals holding management positions over any member of the walk-through team shall not participate in the walk-through.

Input to the walk-through shall include the following:
a) A statement of objectives for the walk-through
b) The software product being examined
c) Standards that are in effect for the acquisition, supply, development, operation, and/or maintenance of the software product
Input to the walk-through may also include the following:
d) Any regulations, standards, guidelines, plans, and procedures against which the software product is to be inspected
e) Anomaly categories

The walk-through shall be considered complete when
a) The entire software product has been examined
b) Recommendations and required actions have been recorded
c) The walk-through output has been completed

3. Inspection

A static analysis technique that relies on visual examination of development products to detect errors, violations of development standards, and other problems. Types include code inspection; design inspection, Architectural inspections, Test ware inspections etc.
The participants in Inspections assume one or more of the following roles:
a) Inspection leader
b) Recorder
c) Reader
d) Author
e) Inspector

All participants in the review are inspectors. The author shall not act as inspection leader and should not act as reader or recorder. Other roles may be shared among the team members. Individual participants may act in more than one role.
Individuals holding management positions over any member of the inspection team shall not participate in the inspection.

Input to the inspection shall include the following:
a) A statement of objectives for the inspection
b) The software product to be inspected
c) Documented inspection procedure
d) Inspection reporting forms
e) Current anomalies or issues list
Input to the inspection may also include the following:
f) Inspection checklists
g) Any regulations, standards, guidelines, plans, and procedures against which the software product is to be inspected
h) Hardware product specifications
i) Hardware performance data
j) Anomaly categories
The individuals may make additional reference material available responsible for the software product when requested by the inspection leader.
The purpose of the exit criteria is to bring an unambiguous closure to the inspection meeting. The exit decision shall determine if the software product meets the inspection exit criteria and shall prescribe any appropriate rework and verification. Specifically, the inspection team shall identify the software product disposition as one of the following:
a) Accept with no or minor rework. The software product is accepted as is or with only minor rework. (For example, that would require no further verification).
b) Accept with rework verification. The software product is to be accepted after the inspection leader or
a designated member of the inspection team (other than the author) verifies rework.
c) Re-inspect. Schedule a re-inspection to verify rework. At a minimum, a re-inspection shall examine the software product areas changed to resolve anomalies identified in the last inspection, as well as side effects of those changes.

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