In this paper we review various organizational issues encountered when GRANTECAN, the Spanish organization responsible for the construction and operation of the GTC telescope, evolved from the construction phase of a large telescope facility into the phase of scientific operation. GRANTECAN now operates and further develops the 10.4m segmented telescope, GTC. The advent of operational pressures to scientifically exploit the telescope enforced a number of organizational changes as priorities shifted towards achieving the best possible level of operational effectiveness. In this paper we will treat the GRANTECAN experience as a case study of the limitations and problems that were encountered throughout this change. We will focus on the processes and strategies applied in order to achieve the necessary changes. We will place our experience in the framework of the McKinsey 7S model, highlight a number of key performance indicators, and will indicate the organizational changes that have taken place, that influenced the way the objectives are achieved. We will present a forward look based on our experience to date.