SOFTWARE REQUIREMENTS ANALYSIS

Software Requirements Analysis (SRA) encompasses those tasks that go into determining the needs or conditions to meet for a new or altered product, taking account of the possibly conflicting requirements of the various stakeholders (beneficiaries or users). Systematic requirements analysis is also known as requirements engineering. It is generally referred to as requirements gathering, requirements capture, or requirements specification.

 

SRA is critical to the success of a development project. Requirements must be actionable, measurable, testable, related to identified business needs or opportunities, and defined to a level of detail sufficient for system design.

 

SRA FUNCTIONS

 

Requirements analysis includes the following functions:

 

Eliciting the Requirements

It is the process of communicating with customers and users to determine what their requirements are. It can also be called requirements gathering.

 

Analyzing the Requirements

Analyzing is determining whether the stated requirements are unclear, incomplete, ambiguous, or contradictory and then resolving these issues.

 

Recording the Requirements

Requirements may be documented or recorded in various forms, such as natural language documents, use cases and user stories or process specifications.

 

SRA PROCESS

 

1.   Stakeholder interviews

Stakeholder interviews are a common method used in requirement analysis. These interviews may reveal requirements not previously envisaged as being within the scope of the project, and requirements may be contradictory. However, each stakeholder will have an idea of their expectation or will have visualized their requirements.

 

2.   Joint Requirements Development Sessions

Joint Requirements Development Sessions are also called Requirement Workshops. Requirements often have cross-functional implications that are unknown to individual stakeholders and often missed or incompletely defined during stakeholder interviews. These cross-functional implications can be elicited by conducting JRD sessions in a controlled environment, facilitated by a trained facilitator, wherein stakeholders participate in discussions to elicit requirements, analyze their details and uncover cross-functional implications. A proficient Business Analyst should be present to document the discussion. Utilizing the skills of a trained facilitator to guide the discussion, frees the Business Analyst to focus on the requirements definition process.

 

3.   Contract-style requirement lists

One traditional way of documenting requirements has been contract style requirement lists. In a complex system such requirements lists can run to hundreds of pages.

 

4.   Measurable goals

Establishing a small set of critical measured goals, rapid prototyping and short iterative development phases may proceed to deliver actual stakeholder value long before the project is half over. Stakeholders and developers can then formulate tests to measure what level of each goal has been achieved thus far. Such goals change more slowly than the long list of specific but unmeasured requirements.

 

5.   Prototypes

Prototypes are mock-ups of an application. Mock-ups allow users to visualize an application that hasn’t yet been constructed. Prototypes help users get an idea of what the system will look like, and make it easier for users to make design decisions without waiting for the system to be built. Major improvements in communication between users and developers were often seen with the introduction of prototypes. Early views of applications led to fewer changes later and hence reduced overall costs considerably.

 

Prototypes can be flat diagrams (referred to as ‘wire-frames’) or working applications using synthesized functionality. Wire-frames are made in a variety of graphic design documents, and often all colors are removed from the software design in instances where the final software is expected to have graphic design applied to it. This helps to prevent confusion over the final visual look and feel of the application.

 

6.   Use cases

A use case is a technique for documenting the potential requirements of a new system or software change. Each use case provides one or more scenarios that convey how the system should interact with the end user or another system to achieve a specific business goal. Use cases typically avoid technical jargon, preferring instead the language of the end user or domain expert. Use cases are often co-authored by requirements engineers and stakeholders.

 

Use cases are deceptively simple tools for describing the behavior of software or systems. A use case contains a textual description of all of the ways which the intended users could work with the software or system. Use cases do not describe any internal workings of the system, nor do they explain how that system will be implemented. They simply show the steps that a user follows to perform a task. All the ways that users interact with a system can be described in this manner. A use case focuses on describing how to achieve a single business goal or task.

 

7.   Software requirements specification

A software requirements specification (SRS) is a complete description of the behavior of the system to be developed. It includes a set of use cases that describe all of the interactions that the users will have with the software. Use cases are also known as functional requirements. In addition to use cases, the SRS also contains nonfunctional or supplementary requirements. Non-functional requirements are requirements which impose constraints on the design or implementation such as performance requirements, quality standards, or design constraints.

 

8.   Stakeholder identification

A major new emphasis in the past was a focus on the identification of stakeholders. It is increasingly recognized that stakeholders are not limited to the organization employing the analyst. Other stakeholders will include; Organizations that integrate or may integrate horizontally with the organization the analyst is designing the system for, any back office systems or organizations, senior management.

 

SRA ISSUES

 

Stakeholder issues

There are a number of ways users can inhibit requirements gathering. Some times users don’t understand what they want or users don’t have a clear idea of their requirements. Problems also rise when users won’t commit to a set of written requirements. At times users insist on new requirements after the cost and schedule have been fixed, which leads to complications. Often communication with users is slow. Users often do not participate in reviews or are incapable of doing so. Some users are not technically sound and hence they don’t understand the development process. Users don’t know about present technology, so they emphasize on outdated technologies. This may lead to the situation where user requirements keep changing even when system or product development has been started.

 

Engineer/developer issues

Problems are also caused by engineers and developers during requirements analysis. Technical personnel and end users may have different vocabularies. As a result, they may incorrectly consider they are in perfect compliance until product delivery. Engineers and developers may try to make the requirements fit on an existing system or model, rather than develop a system specific to the needs of the client. Analysis may often be carried out by engineers or programmers, rather than personnel with the people skills and the domain knowledge to understand a client’s needs properly.

 

ATTEMPTED SOLUTIONS

One attempted solution to communications problems has been to employ specialists in the business or system analysis.

 

Techniques like Prototyping, Unified Modeling Language (UML), Use cases, and Agile software development are also intended as solutions to problems encountered with previous methods.

 

A new class of application simulations or application definitions tools have also entered the market. These tools are designed to bridge the communication gap between business users and the IT organization and also to allow applications to be test marketed before any code is produced. These tools offer:

 

§  Electronic whiteboards to sketch application flows and test alternatives

§  Ability to capture business logic and data needs

§  Ability to generate high fidelity prototypes that closely imitate the final application

§  Interactivity

§  Capability to add contextual requirements and other comments

§  Ability for remote and distributed users to run and interact with the simulation