Insights
Vendor timelines are sales documents. Here is what actually drives ERP duration, what compresses, and what never does, from delivery experience at global scale.
By Christopher Fagan, PEF Consulting Partners. 3 September 2026.
A small business implementing a cloud ERP with standard processes can be live in three to six months. A mid market business with a real estate to migrate should plan nine to eighteen months. A large or multi entity enterprise is a two to four year journey, phased, whatever the vendor deck says. When a proposal shows an enterprise timeline of under a year, it usually means the definition of done has quietly shrunk to a first small go live.
Not the software. Modern platforms install quickly. The duration is set by four things on the client side: how fast decisions get made, how clean the data is, how much customisation is demanded, and how much genuine testing the business insists on. A programme with empowered decision makers, honest data work started early, ruthless scope discipline and protected testing windows runs at roughly twice the pace of one without them, on the same software with the same integrator.
You can compress build, by cutting customisation. You can compress design, by adopting standard processes instead of recreating old ones. You can run workstreams in parallel with strong programme leadership. What never compresses safely is data migration and reconciliation, end to end testing, and the operational readiness of your own people. Every failed programme I have been asked to rescue compressed exactly those three to protect a date, and every one paid the time back with interest after go live.
Watch four dates, not forty. The design freeze, after which change becomes expensive. The first full data trial load, which tells you the truth about your estate earlier than anything else. The start of end to end testing with real converted data, which is where confidence is actually earned. And operational readiness sign off from the people who will run the system, which should be a real gate, not a ceremony. A programme that keeps moving those four dates while holding the go live date is not on time, it is in denial.
Build the plan backwards from a realistic cutover window, protect the uncompressible workstreams first, and hold a contingency of time as deliberately as you hold contingency of money. Then test your own readiness before the clock starts, because the cheapest month you will ever buy is the one you spend getting ready before the integrator arrives.
Take the free ERP Readiness Assessment, or read what the full programme really costs. Independent advice from people who have delivered at every scale.
Related reading: why ERP implementations fail and independent ERP implementation consulting.