Identify the variables and then get responses from various stakeholders.

Each leadership position is different. The process should begin with identifying the outcomes desired from the leadership (more publications, more grant funding, more alumni funding, higher reputation, etc.) and then measure those things. A comparison of the outcomes under different leaders is the way to go. This could be compared to NCAA football coaches. While each coach has a process for preparing their teams to play, they are evaluated on how many championships they win.

There are 5 levels of leadership in the literature that could be used in guiding a standardised system. Level 1, the lowest level is leadership based on position and titles, Level 2, is permission level covering relationships established by a leader in the organisation (people-oriented leader), Level 3 is production level, here a leader has produced a lot to the organisation, his/her production has helped in the organisation development and progress, Level 4, is about leaders who worked on people developement nd developing leaders from people worked with them, The last level and highest level is Level 5, leaders in this category may have contributed to several levels, but people always remember them and their leadership years after they have left the organisartionor even died. These leaders are so unique and influencial. They reshaped the organisation or a country.

I think these levels could be used in assessing leaders and assessing their leadership level. Read the books of John Maxwell.

Thanks to both of you @ James E. McLean & Sammy Azer for your insightful view.

Article Leadership and Local Government Effectiveness: A Framework f...

Deepak Chaudhary, Nice Topic.