Requirements

Requirements artifacts are the documents that are created, managed, and published by business analysts or product management to define the scope and content of the development project.

Requirements must be captured and tracked in a version control system just like any other class of project artifact. In addition, specific requirements must be labeled in a way that allows items to be tracked through the entire life cycle: specifications, implementation, test, release, and support.

The granularity or specificity of the labels employed depends on the rigor of the project. A product with very high quality standards, such as a medical application, will have very detailed requirements that can be tracked in precise detail.

Requirements are often sketched out in natural language and carry informal instruction to the design specification team. A very effective way to organize functional requirements is to use the concepts of User Roles and Scenarios to develop Use cases. This process creates a formal model of the system. The model can then be analyzed to create formals specification of the components of the system.

An advantage of this approach is that formal requirements and specifications can be created as relatively small modules that can be worked on separately. This allows development and test of the modules or components of the system to proceed in parallel and supports the use of an Agile development process.

Customer to Requirements

Customer reports are triaged into categories. Some will be treated as defects in the product.

Defect reports must be prioritized and fed back into the development cycle at the appropriate point. For example, critical defects can be sent directly to development for action while defects with low impact can be sent to design specification group for consideration.

Many customer requests are valuable inputs to the product management, analysis, and requirements gathering process.

All customer reports must be captured in a database, typically one that is optimized for the purpose, called a defect tracking system.

Customer to Implementation

The users, clients, or customers have a direct link to the implementation when the product plans include a maintenance cycle.

Customer reports of problems go to triage, first in Support and later in Engineering. Reports that are approved by both support and engineering as Defects become work items for development and then part of the implementation. A mature process will include ways to expedite this flow.

Test Results to Customer

Test results are usually not shared with customers in detail.

An important measurement of release readiness is test coverage and success rates.

The customer typically gets the results of test results in the form of an available release.

Implementation to Customer

Implementation artifacts delivered to the customer must match the artifacts delivered to test.

It is possible for parts of the implementation to be withheld from the customer, so the released executable code is often a subset of the tested executable code.

The implementation may include internal support for test execution and performance profiling. These features may be turned off for the customer if they affect the behavior or performance of the product.

Another category of implementation artifacts that go directly to customers is screenshots included in documentation.

Implementation to Test

Implementation artifacts - primarily executable code - are the primary channel of information from development to test execution.

Implementation status is another important part of the flow of information. For example, in a large project some parts of the implementation will be ready before others. If the implementation strategy provides a complete testable interface with incomplete logic behind the interface then the test efforts can be directed toward the most advanced parts of the implementation. The test results can to some extent be predicted.

Specifications to Customer Documentation

Design Specifications are an important base of information for user or customer documentation.

Specifications to Test Plans

Functional requirements and engineering specifications are the sources for the structure and content of test plans.

Specifications may include specific provision for tests. For example, instrumentation may be part of the implementation. Components may include functions that are designed to be tested independently of other components and outside of the overall system.

Specifications to Implementation

Engineering specifications define the proposed implementation at an appropriate level of detail.

The intermediate artifacts between the design specification and the implementation are the project plan and task breakdown.

Specifications are often organized as a hierarchy, with general architectural plans as the more general type and implementation guidelines or standards as the more specific types.

Specifications will define the artifacts to build and the relationships between the implementation artifacts.

Specifications are written in a mix of natural and technical language.

Backlog

Some of the artifacts in each class will represent approved, agreed-upon, active, or completed tasks.

Others will represent proposed tasks, work approved but not scheduled, etc. These artifacts comprise the backlog. A backlog is a natural and healthy part of the development process as long as it is managed correctly. One of the themes of this discussion will be to indicate when and how to address items in the backlog.

Here are some of the categories of the backlog.

Requirements that are published but not represented in specifications and/or test plans are in the design backlog.

Specifications that are not implemented are in the engineering backlog.

Implementation artifacts that have not been tested are in the test backlog.

Test plans and automation that have not been executed are also in the test backlog.

Test results that have not been reviewed are in the results backlog.

Customer reports that have not been triaged are in the support backlog.

Customer reports that have been triaged as defects but have not been fixed are in the engineering backlog.

Defects that have been fixed but where the fixes have not been delivered to customers are in the release backlog.

These are the most important components of the backlog.

Requirements to Customer Reports

Customer reports can be evaluated or triaged by reference to requirements.

This allows customer reports and requests to be classified as defects, or as potential enhancements.

The reverse is also true. Requirements may refer to specific customer requests.

Requirements to Test Results

Test results must correspond to requirements in terms of scope. That is, there must be a correspondence between features as described in requirements artifacts and successful test results. This mapping is driven by the coverage of features by test plans.

When required features are ranked by priority, test results can be used to evaluate release readiness. A release cannot be approved until all required, essential, or "release defining" features have been tested and these tests have passed.

Requirements to Test Plans

Requirements artifacts help to define the initial scope of the test plan documents.

Requirements to Implementation

Published project requirements can be compared to system features as described in functional specification artifacts.

An implementation must address the published requirements. All requirements must be represented by some part of the implementation.

An implementation may and often will include elements that are not described in detail by the requirements. While it is not necessary for the requirements to include all features of the implementation in detail, it is recommended that requirements be compared to the implementation to identify any extraneous functions.

Both product management (or business analysis) and engineering must sign off to confirm the congruence of requirements and specifications.

Requirements to Specifications

Requirements artifacts, when published, form the basis for specifications.

Specifications must conform to requirements and may add features.

When requirements and specifications do not agree, negotiations between product management and engineering are required. The results of these negotiations may be captured in Change Request artifacts.

Ownership (or assignment) of responsibility for evaluating the state or quality of agreement between requirements and specifications belongs to both product management and engineering.

Project management responsibilities include the continual measurement of the level of this agreement. Periodic review of the published artifacts is necessary. Specifically, product management must review specifications and engineering must review requirements.

Initial Requirements

The documents that define the initial requirements for a project have their basis outside the project. These documents are the major source of information from the natural world to the project.

Overview

This document will define the scope of our discussion of SDLC.

We begin with the definition of the six primary classes of project artifacts.

1. Requirements
2. Specifications
3. Implementation
4. Test Plans and Automation
5. Test Results
6. Customer Reports

Requirements are documents that describe the initial or general goals of the software to be produced. These are written in a natural language (English in this case) by product management or a business process analyst. Requirements are typically based on intangibles like imagination and insight and form the primary reference documents for a project. These documents are used in turn by the engineering and documentation functions as the basis for more artifacts.

Specifications are engineering documents that describe architecture, design and development plans. These are written in a natural language by engineering management. They are based on requirements documents but include much more detail.

Implementation is produced by the engineering team from specifications and is typically in a language that can be interpreted and executed by a computer. Implementation artifacts are the tangible assets produced by the development process. Some of these assets are transferred from the development group to the customers in the form of a product or system.

Test Plans are produced by test engineering and serve as a framework for evaluation of the implementation. Test plans are based on both requirements and specifications, but not on the implementation.

Test Results are produced by test execution. Results are often in both natural language and machine-readable form.

Customer Reports are natural language documents created ad hoc as a result of the use of the implementation.

Backlog is orthogonal to the other six. It is a measure of the portion of the available artifacts (of any type) that has not yet been used to generate work or other results.

Many other useful terms will be defined in the discussion to follow. The six artifact classes stand out because they are well-understood and can be clearly defined. Most project documents belong in one of these classes.

Each of these artifact classes has a relationship to every other artifact class. Every one of these relationships will be explored at some point in the documents to follow.

Software Development Life Cycle

This blog is written by an expert in the Rational ClearCase and ClearQuest configuration and change management toolset.