Agile methodology In 1990’s, most software developers used to plan for big projects with a lot of people and time, which is called waterfall methodology. It is of course true that for designing mammoth projects such as space station or airline control system needs to cooperate with various companies and agencies, to spend more than 5 years with meticulous documentations. It is mostly not acceptable for small business with small budget because the waterfall methodology takes a lot of time as well as cost when clients require you to fix and go back to the first step. In early 2000’s, 17 software developers organized a union named “Agile Alliance” to suggest better ways of developing software based on interactive communication with clients and company. There are 12 keys of Agile methodology which is basically focused on immediate feedbacks and frequent meetings. There are also series of methods today: XP(eXtreme Programing), Scrum, Crystal Family, DSDM(Dynamic Systems Development Method), FDD (Feature-Driven Development). The most popular thing among those methods is XP which is characterized by test-code based development procedure. Nowadays, the most widely used method is Scrum which has a specific 1~4 weeks period time called “Sprint”. Once the Scrum team decided the size of Sprint, it is not allowed to shorten or extend the period even they will not finish the work on time. If the team could not end the work during the weeks, then it should be modified the workload for Sprint. Each end of Sprint, all relevant people such as developers, business parts, and customers in the project have to attend the review meeting like daily Scrum meeting each day during a Sprint.