How Long Does It Take to Build a Custom ERP? A Realistic Timeline

One of the most common questions we get is: "How soon can we go live?" The answer depends on scope, but for a well-run custom ERP project in India, the realistic timeline is 8–12 weeks from sign-off to go-live. Here's exactly what happens in each phase — and what causes projects to run over.

Phase 1: Discovery (Weeks 1–2)

Before a single line of code is written, the team needs to understand how your business actually works — not how you think it works, but what actually happens day to day.

In this phase, the development team conducts structured interviews with your key stakeholders: sales, purchase, operations, finance, dispatch. They map out every workflow, identify pain points, document edge cases, and produce a detailed functional specification.

What good discovery looks like: You receive a document that describes every screen, every form, every workflow, and every report in plain English (or Hindi). Before development begins, you sign off on this document. This is your protection against scope disputes later.

What causes delays here: Unavailability of key people for interviews, disagreement between departments on how processes should work, or scope creep as more features get added.

Phase 2: Design (Weeks 2–3)

Based on the functional spec, the design team creates wireframes — simple visual layouts of every screen. This is not pixel-perfect design; it's a structural blueprint that shows where each element sits and how navigation works.

You review and approve the wireframes. Changes at this stage are cheap. Changes after development has started are expensive.

What causes delays here: Multiple rounds of feedback on layouts, stakeholders with conflicting preferences, or design decisions being deferred rather than made.

Phase 3: Development (Weeks 3–10)

This is the longest phase and where the actual software is built. Good development teams work in sprints of one to two weeks, delivering working functionality at the end of each sprint for your team to review and test.

You should expect to see progress frequently — not wait eight weeks and get the whole system at once. Weekly or bi-weekly demos keep the project on track and catch misalignments early.

What causes delays here: Unclear requirements (which is why discovery matters so much), client feedback taking more than 2–3 days per sprint, integration complexity (especially with GST systems, payment gateways, or legacy software), and scope additions mid-development.

Phase 4: User Acceptance Testing — UAT (Week 10–11)

UAT is where your team tests the full system against real scenarios before go-live. Your purchase manager raises a test PO. Your sales team creates a quotation and converts it to an order. Your finance team does a test invoice run.

This phase typically surfaces 10–30 issues — some bugs, some enhancements, some misunderstandings of requirements. A well-run development team fixes critical issues within the UAT window; minor enhancements go into a post-launch backlog.

What causes delays here: Testers who aren't available or aren't testing systematically, issues being raised that are actually new feature requests, or critical bugs that require rearchitecting a module.

Phase 5: Go-Live and Training (Week 11–12)

The system is deployed to production infrastructure. Your team is trained — ideally in small groups by role, not in one big session. Real data is migrated (or entry starts fresh, depending on your decision). You go live.

The first two weeks post-launch are the most support-intensive. Expect questions, edge cases, and minor adjustments. A good vendor is available and responsive during this period.

What Simplovative Does to Stay on Schedule

• Fixed weekly check-ins with a single point of contact on your side
• All requirements documented and signed off before development begins
• Fortnightly demos so you see progress and catch issues early
• A clear change request process so scope additions don't silently extend the timeline
• Dedicated project manager who flags delays proactively

The Realistic Answer

For a system with 4–6 modules: 8–10 weeks. For 7–10 modules: 10–14 weeks. For a full enterprise suite: 16–24 weeks. These are for well-scoped projects with an engaged client team. Poorly scoped projects with slow feedback loops can take 2–3× as long.

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