Performance specified maintenance contracts (PSMC) have been operational in New Zealand for over six years. These contracts are driven by key performance indicators that define the expectations of the road agencies. Key performance measures (KPM) are used to monitor progress and performance of the contractor. KPMs are the primary means of the road owner to express its expectations and enforce those through the maintenance contracts. As the effectiveness and efficiency of the KPMs is vital to achieve the desired results, it is essential to examine the effectiveness of the current KPMs to control and direct the maintenance contracts. The paper explores the validity of current KPM definitions and their statistical interpretation in particular. The use of simple statistical terms such as average was found less than satisfactory. The presented data interpretation allows insight into the applied maintenance strategies and highlights potential deficiencies of current KPM definitions. The findings are supported and illustrated by the analysis of network and sub-network level data of two long term maintenance contract in New Zealand. (a) For the covering entry of this conference, please see ITRD abstract no. 0612AR242E.
Samenvatting