After project completion, how to know if worth It?

Great question, and a common confusion in project and investment governance.

NPV is a forecasting tool used at Year 0 to decide whether to invest.

After the project ends, you assess value through realized value, not predictive value.

There are two mature approaches:

Ex-Post Financial Value

You can still calculate a realized NPV by discounting the actual cash flows back to the original baseline date.

Finance teams do this routinely to compare forecasts vs real outcomes.

Alternatively, ROI, IRR, and payback based on actuals give a clear picture of realized value.

Benefits Realization

Beyond pure finance, PMOs assess whether the strategic, operational, and capability benefits expected at Year 0 were actually delivered.

In short: NPV tells you whether to start; realized benefits tell you whether it was worth it.

Both matter, one for prediction, the other for learning and governance.

This is a very valid question, and it ultimately comes down to benefit management. In my experience, benefit management is one of the least practiced processes in most companies. Once a project is completed, handed over to Operations, and the hyper-care phase has ended, Operations and Finance typically return to business as usual and rarely put metrics in place to compare the “before” and “after” states.

In some projects—such as those aimed at reducing machinery downtime or the number of interventions—this follow-up is done to a certain extent (for example, tracking a reduction from 20 interventions per month to 3, and converting that into a financial figure). But in most cases, benefit management either fades away quickly or never truly begins.