Software Requirements Specification For a Mobile App: How And Why To Write Them

“Software requirements specification” is a popular term in software development related environments, and it is still interpreted ambiguously. The difference in understanding of the term often leads to false expectations.

We understand that software requirements are important in application development. Without any written document, it is difficult to properly express the unique app idea to the development company to whom the project will be outsourced for development and to the client for fundraising.

What affects the SRS? How do you evaluate the quality of SRS? Why are professional analytics beneficial? Read this article to find out the answers to these questions.

Why SRS is crucial

First, it is important to establish that SRS is often not a single document or template that can be found online, but a group of documents (so-called “artifacts”).

Good specifications define the project requirements for the team and the client as clearly as possible and make the ultimate goals and objectives transparent. SRS makes it easier and faster to specify the requirements during the development. This allows us to reach the finished product faster.

Specifications can vary significantly for each job. The content depends on the project, production processes, and approach. For example, the specifications for Waterfall app development differ from those for Agile app development. They are like cousins; they have common features, but are different enough that you can tell them apart.

SRS is often considered a general, top-level description of the idea of ​​an application. Some people believe that software requirements must contain as many pages as possible.

We don’t. Our team defines the purpose and content of the SRS for each project. We take into account the tasks of the project, user requirements and quality criteria, while minimizing reliance on standard patterns. As a result, our specifications include sections and blocks that define the necessary and sufficient requirements of a business and development team.

The task of the analyst in the development of TK

When writing SRS, analysts should determine and clarify the requirements for the project based on the requirements of stakeholders. Stakeholders significantly influence decision making in a project.

On the client’s side, there are usually owners, managers, and shareholders. On the development side, there are developers, project managers, QA engineers, among others. On the external systems side (the technical team of the contractor or the client) there are software architects or developers.

Often, top managers participate in the initial stages of the development of business requirements.

However, the requirements for the product tend to come from specific employees or departments who will actively use it. These requirements may or may not be approved by senior management.

It is important to take into account the opinion of the development processes from the technical specialists’ side. It is much better for the project when the team knows who is in the circle of stakeholders and the goals of the application in the beginning, rather than finding out before the release.

The more stakeholders, the more opinions are taken into account. This means that there will likely be a growth in the amount of project documentation. 

SRS writing process

What are the boundaries of the project? The analyst begins to work on any SRS by finding the answer to this question. This includes:

• preparing a general top-level project description
• identifying the business objectives of the project as a whole
• creating a list of all stakeholders
• defining a list of user requirements (who, what, and why).

When clarifying the objectives of the project and the requirements for it, artifacts are created. These artifacts are needed to consolidate the agreements reached between clients and the team, and to clarify the restrictions in the selected implementation option.

Stages of the writing of SRS

1#

At the first stage of the analysis, we prepare an artifact called Vision. This document, like a sketch, defines the boundaries of the future application. In Vision, analysts define the goals of the app so that all stakeholders are on the same page.

At this stage, analysts also determine the main features and their purposes. In other words, we determine what needs to be done, and most importantly, why it needs to be done.

2 #

At the second stage, based on Vision, we can make a rough assessment of the development and a more accurate assessment of the analytics. We determine the structure of the project documentation: which set of artifacts we will need for a comprehensive description of the software, and which rules for change management we will use.

At this stage, it is crucial to understand the purpose of each artifact. We can always make the most detailed set of documents, but this has to include our reasoning. For example, if a client is in a hurry to release a new product in a rapidly developing market, it is better to start work with a minimal set of artifacts.

Creating a complete set of artifacts is not a quick process. It influences the start of development. So it’s better not to create a lot of artifacts, but to determine the goals of creation and the value of all artifacts so we can focus on developing the most important ones.

Stakeholders may have different or even opposite views on artifact goals. In this case, we have to identify contradictions and set the purposes of each document and project overall. We use quality criteria to define the set of artifacts.

Having chosen the quality criteria relevant to the project, we again determine what expectations stakeholders have, make technical adjustments and clarify what is needed to continue working.

Then, we dive deeper into studying the SRS as we specify details of the system’s parts. Later, if we have to change a part of the system or consider new details,  we can meet with the stakeholders to discuss the new developments in the project.

3 #

When working on SRS, analysts often use document templates. They are used as drafts of the structure of documents or as references, and are filled with information for specific tasks. For example, we use such templates as Vision, Role cases, and Description of prototypes. These documents help us see parts of the system from different angles, which allows us to better understand the software requirements.

The choice of templates depends on the project. For instance, if we are working on the admin panel, we probably won’t need prototypes of the interface and a description of the elements. As a rule, in this case, a general description of the main scenarios is enough.

SRS for mobile applications

SRS for mobile applications

It is important to decide which platform the application will be released on. This sets the technical limitations and basic characteristics. For example, in an Android application, the “Back” button on the screen is not required, but in iOS it is necessary since there is no physical back button in iOS.

It is also important to consider that the basis of mobile applications today is their visual part, and the main part of the logic is on the server. Changing the requirements for the visual part often entails the need to rework most of the mobile application. As a result, development costs are rising.

When developing SRS for applications, analysts identify and determine technical requirements and limitations, such as which OS versions should be supported. Some features offered by a client or team when developing requirements for an application may not be available for older versions or may require additional time for implementation.

Do you always need detailed SRS?

From our experience, there are cases when it is important to work on SRS from the beginning of the project, and there are cases when you can start with a top-level description and dynamically start using Agile.

A detailed study of the technical specifications before the start of development is necessary when it is absolutely essential for customers to fix the time and cost of work. At the same time, stakeholders should be sure that changes in requirements after a detailed description and evaluation will be minimal.

SRS is helpful when a client chooses a software development company from a variety of options, comparing the terms of cooperation. A clear and unambiguous SRS ensures that all potential contractors are on the same page. This is exactly what the client needs. It allows you to choose a development team more judiciously.

The more unknown characteristics and fewer details, the wider the scope for interpretation. This is especially true for large companies that often look for contractors in stages. Many people are involved in deciding on the choice of developers. This creates a risk that information will be distorted at one or more stages of the search.

Detailed SRS is optional, and sometimes even harmful to the project, when:

• you need to launch a new product as soon as possible – the time spent on a detailed description of all the requirements is unlikely to pay off, but it will certainly delay the start of development and the release date of the MVP version on the market.
• it is initially clear that the project is long-term, and business cannot formulate in detail all the requirements for the future system: they are still being formed, are changing and will change for a long time.

In such cases, you can start by working out the “Vision” of the project. A team is selected for it that is suitable for technical expertise and experience in product development in the conditions of dynamically changing requirements. With this team, having determined the goals and boundaries of the future system, you can start working using the Agile methodology. With this approach, developers regularly roll out intermediate versions of the system, which allows the customer to effectively adjust requirements and priorities during development.

To wrap up

It’s impossible not to do analytics. In order to develop a project, a team should discuss and clarify all the requirements for it. Part of this process begins even before the development of the system, part occurs during it. The client chooses: either he controls the analytics, or the analytics proceed spontaneously.

The development of SRS, as part of analytics, allows you to control the ratio of the number of parts that are clarified in advance and during implementation.

Software requirements specification helps:

• increase the likelihood that the product will accomplish all the tasks of the business
• more accurately predict the timing of work
• reduce the likelihood and intensity of conflicts in the team as well as misunderstandings between developers
• reduce the risk of distortion of project requirements and major alterations of the visual part and functionality.

When creating and developing SRS, analysts at Azoft take into account the specifics of each project and the requirements for it. They help the client find the optimal balance between the natural desire to foresee everything in advance and the desire to quickly start testing the finished product’s functionality without having to reread the description for the hundredth time.

If you want to order the application, and you are interested in the development of SRS, write to us at info@azoft.com. We will be happy to provide your project with the services of professional analysts.