What are the most efficient personal skills that may help make you better cost controller?

Knowledge of construction management processes, equipments, manpower, market, planning, communication, negotiation,...etc.

Construction knowledge 

Construction equipment knowledge

Construction Market knowledge

Construction Asset management (Company assets and manpower)

Human sources management

Contracting knowledge, planning, communication forecasting and risk management 

Negotiation, Intelligence, Planning,  Scheduling, Information sharing, Leadership