• individuals and interactions over processes and tools,
• working software over comprehensive documentation,
• customer collaboration over contract negotiation, and
• responding to change over following a plan.
• risks stemming from an agile approach: scalability, criticality, design simplicity, staff churn, and staff skills;
• risks stemming from a plan-driven approach: emerging requirements, constant change, need for rapid results, and staff skills; and
• general environmental risks: technology uncertainties, diverse stakeholders, and complex systems.