Common Mistakes: Functional Specification for Web Development

What are pitfalls that companies should avoid when specifying Web applications for internal or external development?

Buerki, Nicolas. E-Consultancy (2004). Articles>Writing>Specifications>Functional Specifications

Functional Specification

A functional specification (or sometimes functional specifications) is a formal document used to describe in detail for software developers a product's intended capabilities, appearance, and interactions with users. The functional specification is a kind of guideline and continuing reference point as the developers write the programming code. (At least one major product development group used a "Write the manual first" approach. Before the product existed, they wrote the user's guide for a word processing system, then declared that the user's guide was the functional specification. The developers were challenged to create a product that matched what the user's guide described.) Typically, the functional specification for an application program with a series of interactive windows and dialogs with a user would show the visual appearance of the user interface and describe each of the possible user input actions and the program response actions. A functional specification may also contain formal descriptions of user tasks, dependencies on other products, and usability criteria. Many companies have a guide for developers that describes what topics any product's functional specification should contain.

Whatis.com. Articles>Writing>Specifications>Functional Specifications

Functional Specification Standard  

In general terms, the functional specification states what the proposed system is to do, whereas design is how the system is to be constructed to meet the functional specification. However in writing it, some consideration of design issues must take place, to ensure a realistic system is specified.

Software Reality. Articles>Writing>Specifications>Functional Specifications

Getting Real, Step 1: No Functional Spec

Don't write a functional specifications document. Why? Well, there's nothing functional about a functional specifications document.

Fried, Jason. Signal vs. Noise (2005). Articles>Writing>Specifications>Functional Specifications

Painless Functional Specifications - Part 2: What's a Spec?

When you design a product, inside and out, the most important thing is to nail down the user experience. What are the screens, how do they work, what do they do. Later, you worry about how to get from here to there. There's no use arguing about what programming language to use before you've decided what your product is going to do. In this series, I'm only talking about functional specifications.

Spolsky, Joel. Joel on Software (2000). Articles>Writing>Specifications>Functional Specifications

Stage Directions Meet Functional Specifications: They Have a Lot in Common

When it comes to modern theater, stage directions—the descriptive text that appears within brackets in a script—are an important piece of the puzzle. They speak for the playwright when he is not there. They provide details about how the playwright has imagined the environment and atmosphere. They describe critical physical aspects of the characters and settings. Stage directions can also be critical in dictating the intended tempo and rhythm of the piece. Whether they establish a production’s overall tone or elucidate particular actions of characters, stage directions help tell the complete story that is in the playwright’s mind. Stage directions accomplish all of this, using a simple convention that structurally separates them from the actual story.

Lepore, Traci. UXmatters (2009). Articles>Writing>Technical Writing>Functional Specifications

So What IS User Requirements Gathering?

Requirements gathering is all about aiming at the right target. It doesn't matter how accurate you are, if you aim at the wrong target, you miss.

Frontend Infocentre (2009). Articles>Usability>Research>Functional Specifications

Using Customer Tests to Drive Development

Test-driven development or TDD is a widely accepted practice used by agile software development teams of many flavors – not only Extreme Programming teams. For each small bit of functionality they code, programmers first write unit tests, then they write the code that makes those unit tests pass. TDD is seen as a design tool, since it forces the programmer to think about many aspects of each feature before coding.

Agile Journal (2009). Articles>User Centered Design>Agile>Functional Specifications

Using Wikis to Document UI Specifications

The role of the interaction designer is to specify the interface’s behaviors and elements, so that engineers know what to build and how the product should operate. This documentation is commonly known as a UI specification or UI spec. There are several applications for authoring a UI spec, with wikis being a relatively new tool. However, designers should be aware of a wiki’s benefits and drawbacks for documentation, since UI specs uniquely reflect a project and its context. The documentation needs are often based on the size of the project, launch date, team dynamics, audience, technology, and the product development process. The development process usually plays a major role in how teams interact and how work is completed or delivered, thus, there is a direct relationship between the UI spec and the process the team is using.

Gremett, Peter. Boxes and Arrows (2009). Articles>User Experience>Interaction Design>Functional Specifications

User Interface Pattern Documentation Review

User interface (UI) patterns have the potential to make software development more efficient. The prospect of such efficiency gains has led to interest in user interface (UI) patterns by individuals and organizations looking for ways to increase quality while at the same time reducing the costs associated with software development.

Stapleton, Patrick. Boxes and Arrows (2009). Articles>User Interface>Documentation>Functional Specifications