How long does a software project take: building a realistic timeline
A corporate site runs 3–5 weeks, e-commerce 6–10, custom business software 8–16. The bands are not the hard part: most of what stretches a timeline piles up on the client side, not in development.
A project quoted at “three months” finishes in seven. The cause is rarely a bad estimate — it is the time nobody counted.
An agency estimates its own work: so many screens, so many integrations, so many weeks of development. That estimate usually holds. What does not hold is the gaps between those weeks: the screen awaiting sign-off, the copy that never arrived, the email nobody answered.
Realistic bands
Once scope is settled and a single team is on it:
- Corporate website: 3–5 weeks
- E-commerce platform: 6–10 weeks
- Custom business software: 8–16 weeks
These are development durations. Discovery is included; content production, data migration and third-party approvals are not. That distinction belongs in the proposal in writing — otherwise a delay becomes an argument about whose fault it was.
Three things that stretch the timeline — all on your side
Decision lag. On a two-week cycle, feedback that takes five days means a third of the project is spent waiting. Name one decision-maker. “Let me talk to the team and come back to you” is the most expensive sentence in any schedule.
Content. Copy, images, product descriptions, price lists. The software finishes and the site sits empty for two months. Start content work in parallel with development, never after it.
Third parties. Payment provider onboarding, e-invoicing integrators, bank POS setup, API access to an existing ERP. None of this moves at your speed or the agency’s, and it can take weeks. Start on day one, not on the day you need it.
What stretches it on the agency side
If scope is not written down, the estimate is fiction — the same reason the price cannot be compared either.
The second is team load. “Our team is available” is not an answer; how many projects that same team is carrying determines your place in the queue. Put names and allocations in the contract — the list of questions to ask in a proposal meeting covers why this matters.
What actually shortens a timeline
Split the scope. Ship the most valuable flow as phase one and leave the rest for later. That is the only honest way to turn an eight-week project into a four-week launch; an agency that says “we’ll do the same work faster” is either skipping tests or hiding overtime in the price.
Write acceptance criteria up front. What “done” means and on what condition you will sign off — settle those sentences early and there is no argument at delivery.
Start with what is unblocked. The interface can be built while integration approval is pending. Ordering the work by dependency alone can cut weeks off the total.
Be wary of a fixed date
An agency that says “two months” without seeing the scope is doing one of two things: hiding the risk in the price, or planning to drop testing and documentation to hit the date. The second looks cheap and sends the bill during maintenance.
What you want to hear: a written timeline delivered with the scope document at the end of discovery, with your own obligations listed as separate line items, each with its own deadline.
If you want to map out your scope and build a realistic timeline together, let’s set up a call. The budget side is covered separately.
