ERP implementation plan: phases from mapping the business to go-live
A custom ERP goes live in phases, each in use before the next starts: a short modeling phase that maps the business and ends with a dated, fixed-price plan; then the records that must be right; then the daily work of each department; then reports and AI. Data migration is its own scoped piece of work, and the requirements' tests are the acceptance tests for each phase.
Pujan Motiwala · Statutory rules checked against the official texts on
Why phases, each in use before the next
ERP projects in Indian SMEs usually fail the same way: people go back to Excel and WhatsApp because the system doesn't match how the business runs, and the old data turns out messier than anyone planned for. Phases that each go live and get used before the next one starts catch both early. You never pay for months of work you can't see, and a wrong assumption costs a phase, not the project.
The phases
| Phase | What it delivers | Done when |
|---|---|---|
| 0. Modeling | A map of the business (entities, workflows, approvals, rules) and a dated plan with a fixed price per phase | The owner agrees the map and the plan |
| 1. Records that must be right | Masters, stock, opening balances, the ledger or the Tally link; migration of what's needed | Counts and balances tie to the old system |
| 2. Daily work, department by department | Sales, purchase, stores, production, dispatch, accounts, as the plan orders them | Each department works in the system, not beside it |
| 3. Portals | Customer and supplier access | Customers and suppliers use their links |
| 4. Reports and AI | Dashboards from the same records; assistants and document reading with human review | Figures trace to records; AI answers match the reports |
The order inside phase 2 comes from the map: whatever the business can least afford to get wrong goes first.
Data migration is its own piece of work
Migration is scoped and quoted separately, before it starts, rather than discovered halfway. Every import is checked against its source, doubtful rows are held for a person, and each import is tagged so it can be removed as one batch. See moving from Tally.
The requirements are the acceptance tests
Every line on the requirements checklist has a test. Before a phase is signed off, run the tests for the lines it covers, on your own data. The same tests made the vendor demo script; using them again at go-live is how you find out whether what was shown is what was built.
How long it takes
It depends on how new the problem is. Something already built for another business can ship in days or weeks; genuinely new ground takes a couple of months, delivered in phases so part of it is in use early. The modeling phase ends with a date for each phase, so you know the timeline before you commit to the build.
What it costs
Published 2026 guides from other firms put a custom ERP for a small Indian manufacturer at roughly ₹3–15 lakh, and a fuller build for a mid-sized manufacturer at ₹15–40 lakh. Those are market figures, not a price list: two businesses that both want "an ERP" can need very different systems, which is why the price is fixed per phase only after the modeling phase. Maintenance after go-live usually runs as an annual contract. Ahrom Labs' terms, and the sources for those ranges, are on the engagement page; what to settle in the contract is in the contract checklist.
Your plan, in one line per phase
Write the plan as a table: phase, what it delivers, the requirement lines it covers, the acceptance tests, the date, the price. If a vendor can't fill that table before the build, the plan isn't ready.
Answer five questions about your business and get the requirements that apply to it, ready to send to vendors.
Most lines here can be tried today on a live system: manufacturing · trading · interiors · how Ahrom Labs builds them
Official sources
- Companies (Accounts) Amendment Rules, 2021 (G.S.R. 205(E), 24 March 2021). Ministry of Corporate Affairs, Gazette of India, October 25, 2026.
- Companies (Accounts) Second Amendment Rules, 2022 (G.S.R. 235(E), 31 March 2022). Ministry of Corporate Affairs, Gazette of India, October 25, 2026.
- Notification No. 10/2023–Central Tax (10 May 2023), amending Notification No. 13/2020–Central Tax. Central Board of Indirect Taxes and Customs (copy hosted by the GST Council), October 25, 2026.
- Advisory: Time limit for reporting e-invoice on the IRP portal, lowering of threshold to AATO 10 crores and above (5 Nov 2024). GSTN (Goods and Services Tax Network), October 25, 2026.
- Notification No. 12/2018–Central Tax (7 March 2018), substituting rule 138 of the CGST Rules, 2017. Central Board of Indirect Taxes and Customs (copy hosted by the GST Council), October 25, 2026.
- Micro, Small and Medium Enterprises Development Act, 2006, sections 15 and 16. Gazette of India (copy hosted by the Ministry of MSME), October 25, 2026.
- Income-tax Act, 2025 (30 of 2025), in force from 1 April 2026. Ministry of Law and Justice, Gazette of India, October 25, 2026.
- Digital Personal Data Protection Act, 2023, section 8. Ministry of Law and Justice, Gazette of India, October 25, 2026.
- Digital Personal Data Protection Rules, 2025 (G.S.R. 846(E), 13 November 2025). Ministry of Electronics and Information Technology, Gazette of India, October 25, 2026.
What this page is not
A guide written by Ahrom Labs from the systems it runs; not legal or tax advice. Statutory lines quote the official text, and the text governs wherever this page differs from it; how a rule applies to your business is a question for your CA. Last updated .
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