What does a Manager do?
Of course "Manage".
Something that needs to be done or delivered in absolutely certain manner!
"succeed in surviving or in achieving something despite difficult circumstances"
"succeed in achieving or producing (something difficult)."
What is to Manage against?
Risk of not able to do or deliver thing against various agreed parameters by keeping constraints intact.
e.g. Quality, On time, Cost, Completeness, Correctness, Reliable, Acceptable, Legitimate, Certainty, Precise, etc...
Guarding the most obvious and important delivery parameters first
Essentially the question is,
What happens when "management" happens?
It is "Risk Free Delivery".
A manager has "Managed well"
when he has managed all the risks "well".
There are internal and external factors which interfere with the agreed delivery
Manager has to "Manage" against all odds about, how will he factors and overcomes every obstacle
Planning, Risk Mitigation, Estimation, Communication, etc. are tools to help "manage"
These tools also need to be used correctly.
e.g. Realistic Plan, Well thought Risk Mitigation, Correct Estimation and enough times repeated, Overly Simplified Clear Communication,...
So there is science in using and talent or art in applying these tools
Manager must be rated on results not on efforts!
Managers metrics is,
What risk emerged,
How he handled it, and
How deliverable achieved as per agreed expectations
If no risks emerged, then it was easy task!
So Manager's true performance is,
when many issues emerged and he did not let delivery affected
More capable managers have more capacity to deal with many and very high risks situations successfully
Leader is more of leading the change for better for everyone and together
He identifies the need and initiates the change process
While Manager is required to take care of every risk to ensure deliveries happen as expected
Individuals and organizations value system, social and legal norms gives boundary framework to carry activity of "Managing" something
otherwise "managing something" can take form of "bribed to get it done"
Manager is for doing things in a right manner that covers all risks against expected delivery
Science of Management is about how you get Right in the Manner.