What is Agile?
A set of values and principles
Nowadays "Agile" means different things to different people but the origin of Agile is from the Agile Manifesto in 2001 when various practitioners of what were at the time called "lightweight frameworks" gathered together to try and find some common ground.
The resulting movement has transformed the project management of software and IT delivery. The values of Agile are based on the realisation that when delivering a complex project in today's fast paced, rapidly changing world the old approach of gathering requirements, designing, developing and testing just isn't appropriate. To deal with the fact that projects often start without complete information, that customers often change their minds and that markets and outside forces increasingly dictate course adjustments "Agile" approaches favour delivering products in an iterative, incremental way allowing continuous feedback from customers and multiple opportunities to adjust and improve plans.
Of all the frameworks and methodologies, Scrum has been the most dominate with over 75% of Agile projects using Scrum or an approach based on Scrum according to the most recent "State of Agile Report".
The Agile Values
Agile Teams value the following...
Individuals and Interactions over Processes and Tools
Working Product over Comprehensive Documentation. ...
Customer Collaboration over Contract Negotiation. ...
Responding to Change Over Following a Plan.