How long these projects really take
Timelines slip for a small number of predictable reasons, and none of them are technical.
Sequence for a first result inside a quarter. Any plan whose first deliverable is a year away will slip, because nothing has been tested against reality until then.
Every implementation partner has been asked how long this will take, and every honest answer begins with a question. That is unhelpful when you are trying to plan, so it is worth setting out what actually decides the schedule.
In our experience it is three things, and technology is not among them.
What decides the timeline
Data quality
The single largest variable. Clean, consistent masters make migration routine. Duplicate customers, inconsistent item codes, and fields repurposed years ago make it the longest task in the plan — and it is discovered rather than estimated.
How fast you decide
Projects wait on decisions far more than on development. Where every question goes to a committee that meets fortnightly, the schedule is set by the committee, not by the work.
How many processes change at once
One process is a project. Four simultaneously is more than four times the work, because they interact and every dependency is a place to wait.
Whether people are available
The people who know how the process really works are also the people running it. If nobody is freed to be involved, the requirements are guesses.
How to structure so slippage cannot compound
- First phase live inside a quarter, always — a plan without one has not been tested against anything.
- One process at a time, each independently useful.
- A named decision-maker who can settle a process question the same week.
- Data cleansing started before the project, by your team, not during it.
- A defined history cut-off rather than migrating everything ever recorded.
- Parallel running scoped to a business cycle, not to a fixed number of weeks.
Why long plans slip more than proportionally
An eighteen-month plan does not fail because eighteen months is difficult to estimate. It fails because nothing is verified until the end, so every wrong assumption stays wrong for the full duration and is discovered together, at the point when changing anything is most expensive.
A phased plan surfaces the same wrong assumptions in month three, when they are cheap. That is the entire argument for phasing — not that it is faster in total, but that it fails earlier and smaller.
Ask any partner what will be working in ninety days. If the answer is a document, the timeline is not real yet.
Project timelines — questions we get asked
Can we go faster by paying more?
Only up to a point, and less than people expect. Adding people to a project constrained by your decision speed and data quality does not help, and often slows things by adding coordination.
What is a realistic first milestone?
Something genuinely in use within eight to fourteen weeks — one process, end to end, with real users. Not a demo environment and not a signed-off document.
Who is usually the bottleneck?
Honestly, availability of your own people, and it is not a criticism. The people who understand the process are the ones running the business. Planning for their time explicitly is the difference between a schedule and a wish.
The work this leads to
Moving from Tally to a real ERP
Most businesses do not need to leave Tally. They need to stop using it for the things it was never built for, and move those onto something else first.
Read itMigrationModernizing FoxPro, VB6 and Access systems
These systems usually encode two decades of business rules that exist nowhere else. The migration risk is not the code — it is losing the rules.
Read itOther guides
What ERP implementation actually costs in India
Most firms answer this with 'it depends, contact us'. It does depend — on a small number of things you can assess yourself before anyone quotes you.
Cost guideWhat custom software actually costs to build
Most quotes cover version one. The questions that matter are what year two costs and what is excluded from the number you were given.
Still weighing it up?
Most of these questions are quicker to settle in a conversation than in an article — particularly the ones where the answer depends on your numbers.