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Motivated by the squeeze on public service expenditure, staffing is an important issue for service systems, which are required to maintain or even improve their service levels in order to meet general public demand. This paper considers Police Patrol Service Systems (PPSSs) where staffing issues are extremely serious and important because they have an impact on service costs, quality and public-safety. Police patrol service systems are of particularly interest because the demand for service exhibits large time-varying characteristics. In this case, incidents with different urgent grades have different targets of patrol officers’ immediate attendances. A new method is proposed which aims to determine appropriate staffing levels. This method starts at a refinement of the Square Root Staffing (SRS) algorithm which introduces the possibility of a delay in responding to a priority incident. Simulation of queueing systems will then be implemented to indicate modifications in shift schedules. The proposed method is proved to be effective on a test instance generated from real patrol activity records in a local police force.

From preliminary design through product sustainment to end of life removal, optimal performance through the entire life cycle, is one of the most important design considerations in engineering systems. There are a number of mathematical modelling techniques available to determine the performance of any system, or process design. This paper focuses on the Petri Net technique for the representation and simulation of complex cases with the future aim of automatically generating a model from the system, or process description. If the model can be automatically generated changes can be investigated easily, enabling different designs to be investigated. Within this research, a Petri Net model is developed for a process of recycling IT assets. The model developed here will be used in future work to validate the automation process. This model is simulated and programmed in Matlab. The model enables the simulation of various flow paths through the recycling process, giving an understanding of the current process limiting factors. These can then be used to identify possible ways of improving the efficiency of the recycling process and enhancing the current IT asset management strategy. The future aim of this research is the automatic generation of a system model for complex industrial systems and processes by converting the SysML–based specifications into Petri Nets.

Automated Guided Vehicles (AGVs) are being increasingly used for intelligent transportation and distribution of materials in warehouses and auto-production lines. In this paper, a preliminary hazard analysis of an AGV's critical components is conducted by the approach of Failure Modes Effects and Criticality Analysis (FMECA). To implement this research, a particular AGV transport system is modelled as a phased mission. Then, Fault Tree Analysis (FTA) is adopted to model the causes of phase failure, enabling the probability of success in each phase and hence mission success to be determined. Through this research, a promising technical approach is established, which allows the identification of the critical AGV components and crucial mission phases of AGVs at the design stage.