mobile app development

requirements important in mobile app development?

mobile app development

Strict and stringent requirements are the basis for successful products. This holds true for any project a company works on. Hence, around 85 of projects having precise requirements are successful in meeting the highest quality standards.

However, there is confusion when app developers encounter the standoff between functional and nonfunctional requirements.

What is the difference between functional and non-functional requirements in app development and software engineering? Does this distinction matter? And why are both functional and non-functional requirements important for any project to hit the mark?

Let us read this article to find out more.

mobile app development

Functional Requirements – what are they?

Functional requirements are basically specifications of the way a software product/application works (i.e. its features). In simple words, functional requirements define what software should precisely do and how the system should respond to inputs. Functional requirements are able to define the software’s goals, meaning that the software won’t work if these requirements are not fulfilled.

mobile app development

Functional requirements define the app’s/software’s goals, meaning that either or both won’t work if the mentioned requirements are not met.

Both functional and nonfunctional requirements are crafted by business analysts. The responsibility of communicating with clients falls upon them as well as determining their needs and wants, and translating them properly into specifications.

Functional requirements might include the following:

mobile app development

  • Administrative requirements.
  • Business requirements.
  • Reporting requirements.
  • Authentication.
  • Certification requirements.

For instance, whenever anyone signs in on any website, they will receive an email notification confirming their registration. During the development stage, sending email notifications is described as a functional requirement.

What are the Non-Functional requirements?

mobile app development

While functional requirements define the system’s fundamental behavior, non-functional requirements set out how the system will conduct such a function. 

Let us revert back to the example of email notifications. The fact that the system will automatically send an email notification is a functional requirement. Non-functional requirements will dictate when the email should be sent (i.e. after 5 seconds of the sign-up).

mobile app development

The following can often be considered as the essential non-functional requirements:

  • Usability.
  • Reliability.
  • Performance.

Unlike functional requirements, non-functional requirements do not form the fundamental pillar of the system. This means the system can still work if the non-functional requirements are not fulfilled.

However, no one should downplay the role non-functional requirements have. While functional requirements focus on the client’s needs, non-functional requirements are heavily user-oriented.

A website taking more than 30 seconds to load will still meet all the functional requirements but will not meet the other requirements (non-functional especially).

Why is the difference between Functional and Non-Functional Requirements important?

Though both functional and non-functional requirements are essential, the question still remains: Is it necessary to distinguish between Functional and Non-Functional requirements? To an extent, it is not important and not necessary as well.

In practice, developers often do not draw the line between both functional and non-functional requirements. Experts from a well-known firm of app development Toronto revealed that developers do execute the products’ features as possibly well as they can.

mobile app development

Nevertheless, the distinction between the functional and non-functional approach is important when to comes to understanding the client’s needs. When the client sets about a project, they have needs and wants that are specific.

Both needs and wants should be converted into the work scope, and here is where the difference comes in handy.

Sometimes, after overseeing the budget and cost, clients can conclude that there are some requirements that can be changed, modified, simplified, or replaced (or all can be done). As per the rule, Changes can only be made to non-functional requirements.

How are these requirements written?

The functional and non-functional requirements are written in a Software Requirements Specification (SRS) document in the following way:

  • Introduction.
  • Overall description.
  • System features.
  • External interface documents.
  • Non-functional requirements.


An app/software cannot be made unless and until both functional and non-functional requirements have been mentioned and specified. These requirements point out the functions of an app and indicate areas needing creation, fixing, improvement and vice versa.

If these requirements are not mentioned then app and software development becomes pointless, even if the idea was among the most unique of all app ideas present.

Mobiles Phone

Leave a Reply

Your email address will not be published. Required fields are marked *