How much time does our own team need to put into an ERP project?

In a mid-sized ERP project, expect internal effort in the order of the external consulting days, and more in projects with many processes. The key roles matter more than the total: a project manager needs at least half of their working time in the intensive phase, and the process owners of the core areas one to two days per week each. Anyone not releasing that time pays for it later in delay.

Why projects drag on: The ERP implementation drags on forever. Why?

Who steers in the project: Who steers your project when it gets hard?

Which roles need how much time

The internal load is not evenly distributed. Four roles carry the largest part. The internal project manager is the most critical: in the concept and test phases this person needs at least fifty percent of their working time, in the go-live phase often more. A project manager running the project alongside a full line role becomes the bottleneck through which all decisions slow down.

The process owners of the core areas, typically finance, sales, production and logistics, sit at one to two days per week across the concept and test phases. They are the ones who describe processes, prepare decisions and later test.

The third role is data ownership. Cleaning master data is work nobody can do for you externally, because only your organisation knows which item is still needed. The fourth are the key users in the business areas who test and later train. Their effort concentrates in the last months before go-live.

Why internal effort is underestimated

The main reason is simple: external days are invoiced and therefore visible, internal days are not. They appear in no calculation and are only felt when deadlines slip or daily business suffers.

The second reason lies in planning. Many projects plan internal involvement as an additional task alongside existing work. That works in quiet phases and collapses as soon as quarter-end, holiday season or a special situation in the business gets in the way. Exactly then decisions sit for weeks while external costs keep running.

The third reason is the test phase. It is regularly planned most tightly and needs the most time, because testing is not clicking but real business transactions with real data. Saving here shifts error discovery into live operation.

What training and onboarding cost

Plan a separate budget line for training and enablement, not a residual amount. Two quantities determine it: the number of users and the number of different roles. Training ten roles is more demanding than training a hundred users in one role.

Training has three parts that are often thought of as one. First the actual training before go-live. Second the materials, meaning short guides for the workflows that genuinely occur in daily work. Third the support in the first weeks after the start, when the real questions come up.

That third phase is the most effective and the most frequently cut. It decides whether users adopt the new system or look for ways around it. A workaround created in the first weeks often persists for years.

How to make internal effort plannable

Three measures have proven themselves. First: release the key roles verifiably, not verbally. A release that is in the calendar and communicated in the team withstands daily business. A verbal assurance does not.

Second: plan the load across the phases rather than as an average. Effort is high in the concept phase, lower during implementation and highest before go-live. Planning with an even average underestimates exactly the critical weeks.

Third: settle cover for daily business before the project starts. The most common cause of project work falling through is not a lack of willingness but a line task nobody takes over. That clarification costs little and saves deadlines.