Functional Specification in Practice: Why Do Most Software Projects Fail?
Across hundreds of projects, a clear pattern emerges. Problems rarely come from developers writing bad code. Far more often, they come from a failure to define what needed to be written in the first place. That is precisely why it is worth investing time in functional specification, needs assessment, requirements gathering, and business analysis before a single line of code is written.
What Gabor consistently sees is that the most painful mistakes are almost always made at the very beginning. Vague requirements, undefined business rules, and poorly grounded technology decisions all take root early, and from that point every subsequent phase of development drifts in the wrong direction. The later a problem surfaces, the more expensive it becomes to fix.
Loginet’s specification service is designed to minimize exactly this risk. Before development begins, we document what you will receive, both functionally and technically, and what it will look like visually. We do not deliver a general situation assessment, and we do not hand over a PowerPoint presentation. The end result is a comprehensive document package that is ready to build from, whether with us or with another vendor.
Why Do We Build So Much on the Prototype?
It is worth pausing here, because this is where our approach differs most from the conventional one. Gabor often tells clients: people do not say yes to documents, they say yes to something they can actually try out.
This phase is essentially a product discovery process: before any development commitment is made, we map out what the system actually needs to do and for whom. A traditional software specification is a document. The client reads it, nods along, and hopes the final product will match what they imagined. This approach frequently breaks down, because the human mind understands working things far better than written descriptions of them.
For this reason, we take a different path. Using vibe coding and AI tools, we produce a working prototype during the specification phase itself. This is not a static wireframe, and it is not a clickable mockup. It is a live, interactive application that demonstrates the system’s operational logic, user flows, and business rules.
Why does this matter so much in practice? Because it lets you make a decision before you are committed. Instead of saying yes to an 80-page document, you are saying yes to something you have actually used. Misunderstandings surface during the specification phase, not in the middle of development, when fixing them costs orders of magnitude more.
Stakeholder involvement also becomes far more straightforward. The requirements gathering process already includes stakeholder interviews, and a working prototype makes those conversations significantly more productive. In practice, this often takes the form of a discovery workshop, where stakeholders across departments can interact with the prototype and align on requirements together. A working prototype is something the CEO can understand, the CFO can try, and the operations team can give feedback on. The development team, in turn, sees exactly what needs to be built: they are working from a live prototype, not interpreting a document.
One important clarification: the prototype is not the final product, and it is not production code. What it is ideally suited for is helping you make a responsible decision about whether to start development at all.
Software Specification Is, in Reality, Business Analysis
The following section is more technical in nature, and we want to flag that upfront. If you are curious about what the actual work involves, it is worth reading.
At the heart of specification work is business analysis: the precise translation between business needs and technical implementation. This is the work of the business analyst, who guides the process from requirements gathering and requirements analysis all the way to defining acceptance criteria. This is a role where business thinking and technical thinking meet, and IT business analysis is what builds the bridge between the two sides.
The tools and formats we use always depend on the project. User stories capture what the user wants and why, typically in one or two sentences. Use cases, on the other hand, describe how a process unfolds step by step, including alternative paths and exceptions. The two formats often coexist within a single project: the user story provides the goal, the use case provides the scenario.
BPMN process maps are one of the primary tools for workflow design, visually representing business processes, actors, decision points, and system boundaries. In our experience, this is one of the most effective communication tools between the client and the development team. We also produce data and system models as part of software architecture and system design, defining data structures, entities, relationships, and integration points.
Every requirement comes with acceptance criteria. These are not added as afterthoughts; they are an integral part of the specification. A requirement is only considered complete when there is a clear, unambiguous way to determine whether its implementation meets it or not.
One of the most valuable outputs of this work is the parallel documentation of the AS-IS and TO-BE states. The AS-IS describes how processes currently work, what systems are involved, what data flows through them, and where the pain points lie. The TO-BE describes how the process will work after the solution is introduced, what technology components it will rely on, and what business outcomes can be expected. Both the development team and the client need this pairing to translate business requirements into a realistic picture of the change, and it gives them a concrete foundation for implementation.
What Does the Client Actually Receive?
The end result of the functional specification process is a structured, usable document package in which every element serves a concrete purpose. It is not a 200-page binder that nobody reads. Alongside the documentation, a working prototype is typically produced, through which the system’s logic, key processes, and user flows can be explored before development begins. The exact composition of the package varies by project, but it generally consists of the following elements.
Problem map and root cause analysis. A structured document recording the identified challenges, their relationships, priorities, and business impact.
Functional specification (SRS). A detailed description of the system’s expected behavior: functions, user roles, business rules, and acceptance criteria. This is the document the development team works from, and it forms the basis of functional design.
Technical specification and architecture documentation. Architectural decisions covering solution architecture and their rationale, a recommended technology stack, system components and their relationships, and non-functional requirements (performance, scalability, security). This forms part of the system specification and is the foundation on which the entire IT system design is built.
API specification. Where integration is required, a precise API description is produced: endpoints, data structures, authentication, rate limiting, and error handling. This ensures that communication between systems is clearly defined from the very start of development.
AS-IS and TO-BE process maps. Visual documentation of the current and desired states, in BPMN or a comparable format. These can be used immediately for internal communication, training, and change planning.
Wireframes and user flows. Schematic designs of the user interface and descriptions of interaction flows, brought to life by the working prototype. These are the visual representation of functional logic and serve as input for UX/UI design.
Build-or-buy decision matrix. A component-by-component analysis of which parts are worth building from scratch, where a mature market solution exists, and what integration strategy is appropriate.
Prioritized roadmap. A phased, scheduled development plan with dependencies, resource requirements, estimated timeframes, and projected business impact. The roadmap also identifies the decision points where the client can initiate a change of direction.
Feasibility analysis. An examination of technical, financial, and organizational constraints. A scenario-based decision framework showing expected outcomes and risks across different resource allocations and approaches.
The Software Specification Belongs to You
The specification package is the client’s property in its entirety. Development can begin with it immediately, whether with us or with another vendor. The client pays to gain a precise understanding of what needs to be built, and that knowledge remains theirs.
