This thesis is concerned with knowledge creation processes within service organizations, specifically in relation to the maintenance function. While bearing in mind the particular context of the study, the thesis argues that maintenance service work, when seen from such a knowledge creation perspective, affords important insights into the dynamic interrelations, links and social interactions within the knowledge creation processes themselves. To date, the knowledge management and organization studies literature tends not to treat these practical topics and theoretical issues in an integrated, holistic manner. The thesis addresses this lack using an in- depth, situated case study of the maintenance division of a major Greek petrochemical refinery. The research adopts an interpretative perspective and makes sense of knowledge creation processes through the theoretical lens of the Unified Model of Dynamic Knowledge Creation (Nonaka et al. 2001), combined with the knowledge activism framework (Von Krogh et al. 1997). Nonaka's framework, which guides data collection and analysis, suggests an approach to the investigation using the so-called SECI process. This process explains how knowledge creation unfolds, utilising the Japanese concept of Ba (which represents the process context), and the concept of knowledge assets (which corresponds to the process content). The explanation of important individual and group roles within knowledge creation processes using Von Krogh's framework integrates these concepts. This use of a process view of knowledge creation helps explain a wide variety of complex and situated interrelations that demonstrate the existence of different modes of knowledge creation. Thus, the approach to process inquiry along with the research design fertilize methodological discussions about research on knowledge creation processes. The core theoretical contribution of the research concerns the provision of a process view of knowledge creation. Other theoretical implications of the research findings relate to insights on the complex nature of the knowledge creation process within a work environment, extensions to the research framework, and recommendations for further conceptual developments. The research also contributes practical implications and insights into, and specific conclusions about, knowledge creation processes and how they might be effectively managed in service organizations more generally.

Stochastic models are developed for the reliability analysis of repairable systems, based upon the non-homogenous Poisson process, as recommended by Ascher and Feingold (1984). In particular, the proportional intensities model (PIM) introduced by Cox (1972), is extended and modified for this purpose. The suitability of the PIM is demonstrated on three groups of hypothetical data sets from the first of these two books. Having identified potential benefits from this approach, the PIM is extended and a new class of generalized proportional intensities models (GPIM) is introduced. These allow for modelling realistic failure patterns by including preventive maintenance activities and explanatory variables to gain valuable insights about cost effective maintenance and replacement strategies. This thesis presents the algebraic theory and develops several variations of the basic GPIM. It also comments on similarities and differences between these and other proposed models for complex repairable systems. Practical applications of the GPIM models are demonstrated on published data sets that were collected from petroleum refineries. We also explore a new area by fitting the models to British Petroleum gas turbine maintenance data from an oil platform in the North Sea, using the Fortran 95 programming language and Mathcad mathematical software. Finally, following the in-depth analysis of the refinery pump data sets and oil gas turbines engine maintenance data, the GPIM model is simulated to minimize the expected cost per unit time over an illustrative fixed horizon of ten years, in order to determine optimal PM strategies. Along the way, weaknesses in current data selection systems are identified, which allow us to make general recommendations for recording maintenance history data. This research was motivated by the Nigerian oil industry where system availability is poor and few maintenance records are kept.

A deficient safety culture has been implicated in a number of organisational accidents from a range of high hazard industries. Despite its implications for safety, many questions about safety culture remain unanswered. In order to contribute to the literature on this topic, this thesis set out to investigate the role of trust in safety culture. The oil and gas industry was chosen as the context for study due to the hazardous nature of its work, the industry’s focus on continuous improvement in safety performance and the interest shown by oil companies in participating in safety research. Leading models of safety culture have stressed the importance of trust in developing and maintaining patterns of safe behaviours at work. This thesis proposed a new model of safety culture based on dual attitudes about trust. This model states that explicit attitudes about trust are part of safety climate and that implicit attitudes about trust comprise some of the basic underlying assumptions that are the deepest level of safety culture. In order to test this model, this thesis developed a method to measure implicit attitudes about trust in an industrial setting. Using this method, two studies of dual attitudes about trust were conducted at different UK gas plants. In both of these studies, different patterns of results were found for measures of explicit and implicit attitudes about trust for workmates, supervisors and the plant leadership, respectively. These findings support the proposed model suggest that explicit and implicit attitudes about trust are separate constructs that may influence different types of safety behaviours.  Positive relationships were found between measures of explicit attitudes about trust and self-report items about safety behaviours like reporting incidents and challenging unsafe acts.  These findings were taken as a step toward validating the proposed model.