of IT value streams. Reference implementations As an emerging area in IT management (see Deployment and Commercial Support), lean IT has relatively few reference implementations. Moreover, whereas much of the supporting theory and methodology is grounded in the more established field of lean manufacturing, adaptation of such theory and methodology to the digital service-oriented process of IT is likewise only just beginning. This lack makes implementation challenging, as evidenced by the problems experienced with the March 2008 opening of Heathrow Terminal 5. British airports authority BAA and airline British Airways, which has exclusive use of the new terminal, used process methodologies adapted from the motor industry to speed development and achieve cost savings in developing and integrating systems at the new terminal. However, the opening was marred by baggage handling backlogs, staff parking problems, and cancelled flights. Resistance to change The conclusions or recommendations of Lean IT initiatives are likely to demand organizational, operational, and/or behavioral changes that may meet with resistance from workers, managers, and even senior executives. Whether driven by a fear of job losses, a belief that existing work practices are superior, or some other concern, such changes may encounter resistance. For example, a lean IT recommendation to introduce flexible staffing whereby application development and maintenance managers share personnel is often met with resistance by individual managers who may have relied on certain people for many years. Also, existing incentives and metrics may not align with the proposed staff sharing. Fragmented IT departments Even though business services and the ensuing flow of information may span multiple departments, IT organizations are commonly structured in a series of operational or technology-centric silos, each with its own management tools and methods to address perhaps just one particular aspect of waste. Unfortunately, fragmented efforts at Lean IT contribute little benefit because they lack the integration necessary to manage cumulative waste across the value chain. Integration of lean production and lean consumption Related to the aforementioned issue of fragmented IT departments is the lack of integration across the entire supply chain, including not only all business partners but also consumers. To this end, lean IT consultants have recently proposed so-called lean consumption of products and services as a complement to lean production. In this regard, the processes of provision and consumption are tightly integrated and streamlined to minimize total cost and waste and to create new sources of value. Deployment and commercial