In his book, Effective Project Management: Traditional, Agile, Extreme, Hybrid, Robert Wysocki identifies four kinds of projects.

Traditional (Waterfall)

• Best approach when both the goal and solution are clear
• Example: Cut-over from one system to another over the course of a few business days
• Controls for risk: By creating a detailed timeline and work breakdown structure (among other things)

Agile

• Best approach when the goal is clear but the solution isn’t
• Example: Iteratively add a well-documented feature to an existing software program
• Controls for risk: Through empiricism - frequently checking that the project outcome is being realized

Extreme

• Best approach when both the goal and solution are unclear
• Example: Prototyping and testing a software program, making big changes along the way in response to feedback and discoveries about scope
• Characterized by: Large amounts of synchronous or near-synchronous communication
• Controls for risk: By time boxing and high-bandwidth communication

Emertxe

• Emertxe is “extreme” spelled backward, pronounced “ee-mert-zee”
• Best approach when the solution is clear but the goal isn’t
• Example: Discover the possibilities that may exist with existing technology - i.e. “We have this cool tech; now what can we do with it?”
• Characterized by: Large amounts of synchronous or near-synchronous communication
• Controls for risk: By time boxing and high-bandwidth communication
• Extreme and Emertxe are flip sides of the same coin