Is there any international benchmark regarding maintenance cost for a cement plant? What is a reasonable figure per ton of cement or ton of clinker? I know it depends on the age of plant, technology, the country, etc.

As you say there is no true reply to your question, however if you can reduce your total maintenance costs below US$5 per tonne then you will be among the best factories in the world!

Is there a set of Critical Success Factors (CSFs) that would generically apply to any player in the cement Industry such that if an organisation does well on these indicators, then it can hope to gain a leadership position in the cement industry?

Big question! And the answers will depend on the markets the cement company is operating within. Current thinking is that a cement company should strive for a balanced scorecard with sound economic performance coupled with environmental and social responsibility. Achieving these requires continuous investment in people, equipment and innovation.