In November 2008 the National Library of Swedendecided to switch classification system from SAB toDewey decimalclassification (DDC). SAB had untilthen been the main classification system in the wholeof the Swedish library field for 87 years. The decisionwas not limited to the national bibliography but alsoapplied to the research libraries of Sweden. Thisprocess developed according to the West Europeantendency to change in favor of the internationally wellspreadclassification system Dewey for more cooperationin the cataloguing process. The public libraries wassimultaneously recommended by SverigesBiblitoteksförening to switch from SAB to DDC in orderto create a uniform classification system for all Swedishlibraries. The purpose of this thesis is to examine howlibrary staff at two Swedish public libraries has beenaffected before, during and after the transition. To do so atheory on organizational change by Nadler and Tushman(1990, p. 80), have been applied. The theory is based ontwo different dichotomies divided into two dimensions;strategic versus incremental change and reactive inopposition to anticipatory change. The method used inthe study are semi qualitative interviews with four andfive informants respectively from two public libraries.Findings show that the transition to Dewey was reactive.According to my informants no larger change for theorganization took place.