Planning in the large: efficient generation of IT change plans on large infrastructures

Abstract

Change Management, a core process of the Information Technology Infrastructure Library (ITIL), is concerned with the management of changes to networks and services to minimize costly disruptions on the business. As part of Change Management, IT changes need to be planned. Previous approaches to automatically generate IT change plans struggle, in terms of scalability, to properly deal with large Configuration Management Databases (CMDBs). To enable IT change planning in the large, in this paper we discuss and analyze optimizations for refinement-based IT change planning over object-oriented CMDBs. Our optimizations reduce the runtime complexity of several key operations part of refinement-based IT change planning algorithms. A sensitivity analysis shows that our optimizations outperform SHOP2 - the winner of a previous comparison among IT change planners - in terms of runtime complexity for several important characteristics of IT changes and CMDBs. A cloud deployment case study of a Three-tier application and a virtual network configuration case study demonstrate the feasibility of our approach and confirm the results from the sensitivity analysis: IT change planning has evolved from planning in the small to planning in the large.