Software Requirement Specification (SRS) is nothing but detailed documentation that outlines the functional and non-functional requirements of the software application that is to be developed. The SRS is created on the basis of the agreement between the contractors and the customers. It also includes use cases to software system interactions. SRS must be in line with other essential documents such as system requirements specification.
Table of Content
1. What is a Software Requirements Specification (SRS) Document?
A Software Requirements Specification document is an integral part of the bespoke software development life cycle as it gives a complete overview of the software project. If the SRS is perfectly defined, then communication between the modules, hardware, and human user interactions will go great. The writing of SRS documents is carried out with the involvement of business analysts, lead developers, and project managers. Before launching a new software product, writing an SRS is a very crucial step.
The Software Requirement Specification holds a huge amount of information like –
- Functional & Non-Functional Requirements
- Product Functionality
- Tech-Stack to be Used
- Development Process
- Delivery Estimates
- Risks Handling
- Use Cases
- Assumptions, Constraints, & Dependencies
2. Why is SRS Document Important in Custom Software Development?
Creating a system requirement specification for software is one of the most important things to start with. It characterizes the objective and scope of the software. The SRS is a document that clarifies the owner’s requirements, market requirements for the product, and development requirements. If the specifications are clear and complete, it can prevent spending more time correcting the errors and reimplementing the software features. Through SRS, the dedicated development team can build the software and ensure that it has all the user wants’ essential features. It is a document specifying all the necessary and basic features to make the app work.
Besides this, the technical specification is also taken as a reference for the development team’s time and cost estimation. By taking all these points into considerations, writing the specification for the custom software development project is essential.
3. Key Components of an SRS Document
One of the most critical components of the SRS document of any project is the description of the functional requirements of the system, which are provided to the software development team by the customer. The functional requirement is considered as the goals of the new system. In the functionality section, all the features and alternative organization methods are well-organized. Besides this, the custom application development tools like modeling tools and requirement tools are employed to hold the functionality. Some common types of functional requirements are –
- Reporting Requirements
- Legal Requirements
- Authorization Levels
- Business Rules
- Transaction Handling
Reliability is a component that sees to it that the software system consistently works well and performs all the functions without failure. Reliability addresses the user’s concern for the failure of the system. Therefore, while specifying the system’s reliability requirements, the development team should follow suggestions like –
- Mean Time To Repair (MTTR)
- Mean Time Between Failures (MTBF).
The usability section in the SRS document is the ease with which the users can learn and operate the system by preparing inputs & interpreting the output. The usability specifies the required time for training the different types of system users and time for the measurable tasks for particular tasks. The usability requirement must support the following perspectives for its users –
- Efficiency of use
- Low Anticipated Workload
4. Performance Requirements
The performance requirements is one of the components that specify how the system works and outlines its response time. Assumptions and dependencies might affect the performance of the system. Besides this, it notifies the response time of the transactions, throughout & capacity of the system, the resource utilization information, and the details about the future upgrades. Also, the performance requirement must make it clear for the users what will be the system’s action-response time. If it is low, how can the client improve it to make the workflow smooth?
Security is an essential aspect of the custom software development process. The SRS defines the system’s security aspects and the user’s concern for how the software system is safeguarded. The security component also sees to it that the system is safe against all the intrusive faults. It should also answer a user’s query about the system login mechanism being secured.
6. Limitations & Constraints
The details about the limitations or any other constraints that may affect the software to some extent are specified in the software requirement specification document. Any sort of hardware limitations is also included here as the users must have a clear idea of how the software will work and what hardware support it will need.
7. Software Interface
The software interface section in the SRS document defines how well the software can communicate with other applications and does it couple well or not. This aspect is necessary as there might be a need for the software to work with another system to fulfill the client’s requirements. This section satisfies the user’s concern on how easy it will be to interface the system with another application. It is important we must know about external interface requirements of your software product.
For each interface in the software, define:
- Details of the interface
- Purpose of interfacing software
8. Hardware Interface
The hardware interface enables the users to know how portable the software system and will be easy to transfer from the current hardware system to another to use the system. Few common aspects like the portability of the data, programs, developer documentation, and end-user affect the most when eliciting the hardware interface requirements. Besides this, the hardware interface must define the cost of the process.
9. Licensing Requirements
This section defines the licensing requirements and the cost of the software system. It answers the user’s query about the system licensing details like its duration and cost. The licensing requirements specify the possible ways that the users can purchase the software. For instance, automated or manual delivery of the license. Besides this, it also describes the types of licenses and restrictions to be applied to the software.
4. Methods to Collect Information for SRS
Information gathering is one of the most important factors in the software requirement specification process to ensure the project’s success. There are different methods to ensure the development team receives the optimal requirements. Here are some of these methods –
With questionnaires or surveys, the data analysts can collect information from a large number of audience in a relatively shorter period. This method is helpful when you have stakeholders in different geographical locations. The questionnaires focus on asking questions about the project objective and end user’s requirements. The questions can be like – What features do you need in the system? Who will deliver the input and the output details for the features? What will be the outcome of the system? What next is in line?
2. One-on-One Interviews
One-on-one interviews can help in identifying the primary sources that users will want to have in the system. Here the data analysts interview the stakeholders working on the current system and are going to use the new software. The purpose of the interview is to ask open-ended questions that help obtain valuable information from various individuals about the current system and their expectations from the new system.
3. Group Interviews
By conducting group interviews of the people from the same position helps in gathering the information much faster than one-on-one interviews. With group interviews, more thoughts can be generated, and a clear perspective can be identified from the entire team who is going to use the system.
4. Analysis of Current Documentation
Analyzing the system’s current documentation is a useful technique for collecting SRS information as it gives a clear idea of the working pattern of the business that is going to use the new software system. It also presents the details about the stakeholders involved in the system. This can help the analyst prepare interview questions or surveys for the stakeholders and get additional requirements.
5. User Observation
Interviews and questionnaires provide the user feedback based on the questions asked by the software development team, but the direct user observation can give precise and well-suited requirements that the team is looking for. To get a better understanding of the working style of the business or the current system they are using, the analyst can observe the user. This method enables validating the previously collected data and collecting the correct requirements for creating a system.
6. JAD & AJAD
Joint Application Development (JAD) is a contemporary method of collecting information introduced to solve users’ problems. It reduces 40% of the time as the users, and the key members of the system are involved in the process. The aim of this method is first to get the design right and then reduce different iterations.
Automated JAD (AJAD) is a newer method to collect SRS information. The goal is to encourage team interaction and keep the technology as the centerpiece. Using AJAD, the analyst can identify business activities and data to display results.
5. Benefits of Writing an effective SRS
The good practice of the software requirement specifications enables the software developers to create a user-centric system and achieve the following advantages for developing a custom software –
- SRS specifies the problem of the application that requires to be changed according to the customers’ demand.
- It offers validations to the hierarchy of requirements and strategies of the development team.
- The SRS is a complete and accurate document of logical statements.
- It showcases the needs and preferences of the end-users.
- Its functional requirements give the best implementational approach to the software developers.
- SRS holds the technical requirements that show what the system is required to do.
Software requirement specification document is a must when the software development company is creating a new project. It is useful for both the customers and the development team as it results in the system’s outcome. The above-listed points can help follow good practice of the SRS, which can eventually benefit in the successful development of the project as per the user’s requirements.