Hey sarathpillai.

Do you have any data you can use to get a distribution of the relevant engineers?

If you have a bunch of data for all engineers then you can use a subset of that data (also known in statistics as a conditional random variable) and then either calculate the median or the mean of that distribution.

Alternatively if you want an interval, then you can get a confidence interval (typically 95% is used) and report that.

In terms of the tools to calculate things like this, you can use anything from Excel to statistical packages like R or SAS.