Why estimating software projects is hard — and how we tackle it at Twelvedevs

But before we dive into how we estimate, let’s unpack why accurate estimation is so difficult, and what we do to minimize those challenges.

Many teams jump straight into time and budget discussions — but if you don’t fully understand what you’re building, schedule estimates won’t hold water. At Twelvedevs, we emphasize defining scope and complexity first. We break down the system into functional modules, define assumptions, and validate unknowns before assigning timelines.

Stakeholders often treat early estimates as promises. The reality? Early-stage projections are based on limited information — and should be treated as directional rather than definitive. We present every estimate as a range (e.g., 5–7 months), reflecting known risks and assumptions.

We also communicate confidence levels alongside each scenario and explain the trade-offs:

Lack of accurate records of past project performance, making estimation guesswork. At Twelvedevs, we’ve built a knowledge base of benchmarked estimates and actuals. This lets us calibrate predictions based on real-world outcomes — reducing uncertainty and improving reliability.

Everyone wants software “faster,” but compressing delivery often comes at the cost of quality and long-term maintainability. We educate clients on the critical path, explain trade-offs, and collaborate to define MVPs when speed is a top priority.

These are more common than greenfield builds — and often more complex to estimate. We consider:

Estimates are made using a combination of analogy-based reasoning and historical data, rather than standard “new build” models.

Small doesn’t mean simple. These projects depend heavily on the experience and efficiency of individual contributors. In such cases, we use bottom-up estimates provided by the actual developers who will own the work, often supported by personal performance data and past delivery rates.

Entering into unfamiliar areas — new industries, technologies, or product categories — brings high uncertainty. We approach these cautiously:

Accurate project estimation is more than just a numbers game — it’s the foundation for successful delivery, clear communication, and lasting client trust. At Twelvedevs, we’ve refined our approach to ensure every estimate reflects real-world conditions, technical complexity, and business priorities. Here’s how we turn uncertainty into informed, actionable planning.

Every accurate estimate begins with a clear understanding of what we’re building. During this phase, our team works closely with the client to uncover the full scope of the project — from business goals and technical requirements to potential constraints and risks.

We ask the right questions early to avoid surprises later. By breaking down the project into manageable components — features, workflows, integrations — we ensure no critical detail is missed. This phase lays the groundwork for realistic, risk-aware estimates that reflect both the what and the why behind the project.

With the scope clarified, the next step is translating high-level requirements into actionable components. Our RFx team breaks the project down into granular work units — features, modules, or user stories — allowing us to assess effort more precisely and identify technical dependencies early.

This decomposition not only improves accuracy but also helps align teams on what’s being built and why. The key is to strike the right balance: detailed enough to capture complexity, but not so exhaustive that estimation becomes a project of its own. This structured breakdown lays the foundation for effort allocation, timeline planning, and risk assessment across all stages of development.

Accurate estimation doesn’t happen in a vacuum — it’s built on experience. At Twelvedevs, we tap into a deep repository of historical project data to inform our estimates. This includes timelines, team velocity, technical challenges, and actual delivery outcomes across a wide range of software solutions.

By referencing similar past projects, we benchmark new estimates against real-world performance. This not only increases accuracy but also reduces uncertainty — especially for complex or custom builds. Our ability to draw on proven patterns allows us to offer clients realistic projections, not guesswork.

Even with detailed planning, software projects rarely unfold exactly as expected. Shifting priorities, technical hurdles, and evolving requirements can introduce delays or scope changes. That’s why we embed risk buffers directly into our estimates — typically 10–20% — based on the complexity and uncertainty of each phase.

Estimation at Twelvedevs is a team effort. We bring together developers, architects, project managers, and domain experts to ensure every angle — technical feasibility, delivery capacity, and operational complexity — is accounted for. This collaborative approach leads to estimates that are not only more accurate but also more aligned with how the project will be executed in reality.

By involving those who will actually build and manage the software, we avoid blind spots and unrealistic assumptions. Developers contribute deep technical insight, while project managers flag resource constraints, cross-team dependencies, and delivery risks.

Software estimation is both a science and an art. It requires rigor, transparency, and experience — not just calculators. At Twelvedevs, our RFx and engineering teams work hand-in-hand to produce estimates that are:

By communicating uncertainty, offering scenario ranges, and using data to drive projections, we make sure that estimation becomes a trust-building tool, not a point of friction.

Would you like to see how we estimate your project?  Get a free estimation consultation and start with clarity.