Understand the Key Principles of Detailed Functional Specifications
After working with your team to produce the technical specifications, you now need to go into more detail in your documentation. This will help your developers to build the application as accurately as possible. This step in the process is appropriately named the “detailed specifications” step.
You’re now at the last step in the V-model (step 4) before coding (step 5). You’ll need to create a document called the “detailed specifications document.”
The detailed specifications document serves as an in-depth guide for developers during the development phase of the project. It contains:
A detailed description of the functionality: It provides details for each function that the product or system needs, including how it should behave and interact with other parts of the system.
Information about the user interface: It also includes details about the user interface, such as button position, navigation, data entry fields, etc.
Technical requirements: It might also include information on technical requirements, including the required hardware and software, protocols to be used, performance requirements, etc.
Data flows and diagrams: A detailed specifications document often includes data flows and diagrams describing in detail how data flows through the system and how the different parts of the system interact with each other.
But why create a separate document? Couldn’t I just put the functional and technical specifications in a single document?
Great question! I’m going to give you a three-part answer to explain why this document is needed!
Level of detail: The detailed specifications document contains much more detail than the functional or technical specifications. While the functional and technical specifications can provide an overall view of what the system will do and how it should do it, the detailed specifications explain exactly how each piece of functionality will be implemented.
Target audience: While functional specifications are generally written for clients and end users and technical specifications are for system architects and developers, detailed specifications are aimed precisely at the developers who will be working on the project. The document serves as a guide to how the project will be implemented.
Focus: Functional specifications focus on the “what” and technical specifications focus on the “how,” while the detailed specifications focus on “how exactly.” There’s a level of detail that is simply not present in the other two types of specifications.
Ensure High-Quality Detailed Functional Specifications
As project manager, you’ll be coordinating the production of the detailed specifications as you did with the previous documents (functional and technical specifications). It will be your responsibility to define a detailed documentation plan to ensure that each contributor can add the part related to their area of expertise.
To ensure document quality, you need to include concepts and topics that will make the developers’ work easier.
I would suggest five relevant topics that should appear in the detailed specifications if you want to produce a high-quality document. The table below shows each section title, expected information, and the role of the contributor who will be involved in writing this section.
Introduction and Glossary
Section | Description | Written by |
Introduction | This section must give an overview of the whole project, its context and objectives, and a brief description of the application. | Project Manager and/or Business Analyst |
Scope | This section describes exactly what is and is not included in the project. It defines the project boundaries. | Project Manager |
Glossary | This section provides definitions for technical terms and acronyms used throughout the document. | Business Analyst and/or Developers |
Functionality and User Interfaces
Section | Description | Written by |
Detailed Functionality | Each function within the system is detailed here, including descriptions of how it works, how it interacts with other functions, and any rules or exceptions. | Business Analyst and/or Developers |
User Interface | This section details the user interface design, including the navigation, element positioning, colors, fonts, etc. It might also include mockups or drawings. | UX/UI Designer |
Technical and Integration Requirements
Section | Description | Written by |
Performance Requirements | This section describes the performance requirements for the system, such as speed, capacity, availability, etc. | System Architect and/or Developers |
Security Requirements | This section describes the security requirements, such as encryption protocols, user role and permission management, data protection, etc. | System Architect and/or Developers |
Integrations | If the application needs to be integrated with other systems, this section describes these integrations in detail, including interface protocols, data formats, etc. | System Architect and/or Developers |
Data Flows and Diagrams | This section contains diagrams showing how data flows through the system and how the different parts of the system interact with each other. | System Architect and/or Developers |
Testing Requirements
Section | Description | Written by |
Testing Requirements | This section describes the criteria that must be met by the system for the testing to be considered successful. It might include specific test cases. | QA Engineer and/or Developers |
Change Management
Section | Description | Written by |
Maintenance and Updates | This section provides information on how changes will be managed and how the document will be updated. | Project Manager |
After defining the detailed specifications, you’ll need to think about the development and testing steps. Let’s see how you can optimize your work during these steps.
Facilitate the Development and Testing Process
As project manager, you need to contribute to improving and facilitating the development and testing phases. There are two keywords to keep in mind: testability and traceability.
These two concepts are essential in ensuring you develop high-quality software.
Testability is a measure of how easy it is to check that a system is working correctly. Software is considered to be testable if tests are repeatable, predictable, and effective. To achieve testability, you need to ensure that you:
Write testable specifications: When writing detailed specifications, you need to check that they are clearly testable. This means that each specification must be clear, unambiguous, and verifiable. For example, rather than saying, “The software must be fast,” you should say, “The software must load the home page in under 2 seconds.”
Coordinate the testing: You need to coordinate all testing that will be carried out on the software. This can include unit testing, integration testing, system testing, and acceptance testing.
Wait, I’m lost. You’ve mentioned unit, integration, system, and acceptance testing. What do they mean?
Unit testing will test a single piece of code in isolation.
Integration testing will test if multiple code elements work together correctly.
System testing will test the full set of functionality developed.
Acceptance testing allows real users to test the application in its entirety and check if the functionality meets all their needs.
Here are some examples of an autopilot application for an aircraft that I’m going to use to explain what these different types of testing involve:
Testing Type | Description |
Unit Testing | Check that each button on a dashboard works individually. For example, the button to start the engine will start the engine. |
Integration Testing | Check how these buttons work together. For example, when you start the engine and increase the power, does the aircraft accelerate correctly? |
System Testing | Test the overall functionality of the aircraft. Does the aircraft take off, fly, and land correctly when using autopilot? |
Acceptance Testing | The pilots (users) test the autopilot software. Do they find the system easy to use? Does the system let them control the aircraft safely and effectively? |
Each of these testing types helps to ensure that the autopilot software works safely and correctly.
If the testing fails, what do I need to do?
If the testing fails, you need to work with your team to identify the root cause of the problem and make the required changes to resolve it. Once you’ve implemented these modifications, you need to retest to check that the problem has been properly corrected.
At this point, each time a test fails and a fix is made, it’s important to keep an audit trail of these changes. This brings us to the importance of traceability.
Traceability is the ability to retrace the history, usage, or location of something. In the context of a software development project, this refers to the ability to track requirements from their origin, through their development, to their final delivery.
To provide traceability, you must:
Track the requirements: You need to have a system in place to track requirements throughout the project. This could involve using a project management tool (e.g., Jira, Monday, Wrike) or a spreadsheet to monitor them. Each requirement must be clearly identified (e.g., with a unique id), and its status must be regularly updated.
Document changes: Every change to a requirement must be recorded. This should include who made the change, why it was made, and when it was made. For developers modifying their code, this can be done using version control tools, such as Git, which record all changes to the source code and the reasons for these modifications.
In summary, you play a key role in the process of developing and testing the software. By ensuring that everything is testable and traceable, you’ll be able to improve the software quality and make life easier for the whole development team.
Maximize Management and Communication Using Detailed Specifications
Your role is to ensure that your project specifications are fully aligned with the identified requirements and constraints. This might seem like a difficult task, but by following a few key principles, you’ll feel confident that your detailed specifications document is aligned with and meets the requirements.
Coordinate the Requirements
Ensure that the user requirements and the software specifications match up. If a requirement changes, the specifications must be updated in response.
Okay, but if I change the specifications, this could affect the budget and timelines, couldn’t it?
Yes, it could! You need to be aware of how much these changes cost and how much time is needed to create each part of the system. You have to identify what your users really need and how they’ll be using what you build. Then you need to estimate how much time and money will be needed to complete each task so that you can do everything without exceeding the budget or the deadline.
Manage Constraints
All projects have constraints, such as time, money, resources, or technology. You need to identify and manage these constraints, understand which are the most important, and find solutions when required.
How can I find solutions?
Once you have your list of functions together with their estimated costs and build times, you need to sort them by importance. Work out what is essential for the project and what could potentially wait. If a feature is too expensive or would take too long to develop, think of alternatives, such as using an existing tool or modifying some functionality you already have.
Coordinate and Communicate
Your specifications need to match the business requirements and be clearly explained to everyone. You must demonstrate how each function fits into the overall system.
Make sure your specifications match the business requirements and integrate seamlessly with existing systems. Communicate these details clearly to all stakeholders—users, developers, testers, and managers—to ensure that everyone agrees on the planned system functionality.
By following these principles, you can be sure that your specifications are aligned with the requirements and constraints of the project.
Over to You!
Background
As the IT project team manager at AirGalaxy, your role is to understand the technical details written by the technical team and to link them back to the functional specifications created for the project. This means you need to understand which technical component contributes to which function.
To do this, you’ll need to use the information provided by your technical team, detailing what each part of the software does.
Instructions
In the Notion template created especially for the AirGalaxy project, you need to add all of the technical components related to each function specified in the corresponding column.
This will enable you to see how each component contributes to delivering the application functionality.
Let’s Recap
The detailed specifications document is a detailed guide to help developers build software, providing comprehensive information about the functionality, user interface, technical requirements, and data flow.
The detailed specifications document is not the same as the functional and technical specifications. It contains more detail and is geared specifically toward developers, focusing on “exactly how” to build things.
A good detailed specifications document makes testing easier and provides full traceability for the software. The testing verifies that the software functions correctly, and traceability means you can track the history of every change.
As project manager, you need to ensure that the detailed specifications are aligned with the project requirements and constraints.
While producing detailed specifications, it’s a good idea to use diagrams to clarify the functionality that needs to be built. Let’s explore this further by creating some diagrams!
