Lean IT is the extension of lean manufacturing and lean services principles to the development and management of information technology (IT) products and services. Its central concern, applied in the context of IT, is the elimination of waste, where waste is work that adds no value to a product or service.
Although lean principles are generally well established and have broad applicability, their extension from manufacturing to IT is only just emerging.] Indeed, Lean IT poses significant challenges for practitioners while raising the promise of no less significant benefits. And whereas Lean IT initiatives can be limited in scope and deliver results quickly, implementing Lean IT is a continuing and long-term process that may take years before lean principles become intrinsic to an organization’s culture.
Lean IT promises to identify and eradicate waste that otherwise contributes to poor customer service, lost business, higher than necessary business costs, and lost employee productivity. To these ends, Lean IT targets eight elements within IT operations that add no value to the finished product or service or to the parent organization,
Although Lean IT typically entails particular principles and methods such as value streams and value-stream mapping, Lean IT is, on a higher level, a philosophy rather than a prescribed metric or process methodology. In this way, Lean IT is pragmatic and not agnostic. It seeks incremental waste reduction and value enhancement, but it does not require a grand overhaul of an existing process, and is complementary rather than alternative to other methodologies.
Agile, Scrum and Lean Software development:
Agile is a set of software development methods that originated as a response for the indiscriminated use of CMMI, RUP and PMBOK creating fat and slow software development processes that normally increased the lead time, the work in progress and value/non value added activities ratio on projects and includes methods like XP, Scrum, FDD, AUP, DSDM, Crystal, and others.
Scrum is one of the more well known agile methods for project management, and has as one of its origins concepts from Lean Thinking. Scrum also organizes work in a cross-functional, multidisciplinary work cell. It uses some form of kanban system to visualize and limit work in progress, and follows the PDCA cycle, and continuous improvements, that is the base of Lean.
You can find more about Agile and Scrum here: Agile-Scrum-Project-Management.com.