Subject: Software Engineering

Topic: Quality Management

Difficulty: High

A baseline is a reference point in the software development life cycle marked by the completion and formal approval of a set of predefined work products. The target of a baseline is to reduce a project's vulnerability to uncontrolled change by fixing and formally change controlling various key products at critical points in the development life cycle. Baselines are also used to identify the aggregate of software and hardware components that make up a specific release of a system.

Baseline purpose: The purpose of a baseline is to provide:

Effective progress points within the system development life-cycle.

A basis for change control in major in project phases.

A stable reference for future work.

Intermediate and final points for assessing the fitness for purpose of project work products.

Effective baselines have the following characteristics:

A baseline must be associated with the production and formal approval of a physical deliverable such as a document or hardware/software component.

All items associated with a baseline must be placed under formal change control.The statement of system requirements (functional baseline) .High level design (allocated baseline)

Baseline Progression

Specifying a baseline. Baselines are defined by:

The names of the physical item(s) which constitute the baseline (e.g. design document, code unit)

The point in the project where the baseline is expected to be complete (e.g. at the end of a project phase)

The method to be adopted to approve baseline items

The individuals responsible for approving baseline items (approval authorities).

The verb "to baseline" refers to the act of placing an approved item under formal change control. A baseline item cannot be changed without the approval of its designated approval authority.

A work product is referred to as a "baseline" when it has been formally reviewed and agreed upon and can only be changed through formal change control procedures. A baseline work product may form the basis for further work activity(s). Software Configuration Management

Software Configuration Management is a set of activities carried out for identifying, organizing, and controlling changes throughout the life span of computer software.

During the development of software change must be managed and controlled in order to improve quality and reduce error. Hence software configuration management is a quality assurance activity that is applied throughout the software process.

To manage and control Software Configuration Item (SCI), each should be separately named and organized using object oriented approaches.

The SCM process defines a series of tasks that have four primary objectives:

• To identify all items that collectively define the software configuration (Identification).

• To manage changes to one or more of these items (Change Control).

• To facilitate the construction of different versions of an application (Version

Version Control

Version Control Combines procedures and tools to manage different version of configuration objects that are created during the software process.A version control system implements or is directly integrated with four major capabilities:

• A project database that stores all relevant configuration objects,

• A version management capability that stores all version of configuration object,

• A make facility that enables the software engineer to collect all relevant configuration objects

• Construct a specific version of the software.

A number of version control systems establish a set – a collection of all changes (to some baseline configuration) that are required to create a specific version of the software.

“Changes set” captures all changes to all files in the configuration along with reason for changes and details of who made the changes and when.

Change Control: Change control is manual step in software life-cycle. Change request submitted and evaluated to assess technical merit, potential side effects, overall impact on other configuration object and system function, and project cost of change.The result of the evaluation are presented as a change report, which is used by the change control authority(CCA) – A person or group who make final decision on the status and priority of the change.An engineering change order (ECO) is generated for each approved change.

The ECO describes the change order to be made, the constraints that must be respected, and the criteria for view and audit.The object to be changed can be placed in a directory that is controlled by software engineer making the change. As an alternative, the object to be changed can be “checked out” of the project database, change is made, and appropriate SQA activities are applied.