System safety concept resources

The concept of structural materials made of renewable resources shows the enormous potential of this new class of materials. In this research project together with the Schuberth Helme GmbH company (subsidised by the Ministry of Food, Agriculture, and Forestry of Lower Saxony), the goal is to develop an industrial safety helmet made of a minimum of 85% of renewable resources. An appropriate fibre/matrix system based on the concept of the biocomposite materials was developed which fulfils the DIN EN 397 German Industrial Standard requirements for industrial safety helmets. While working on this pure material basis, a manufacturing process with appropriate productivity and quality had to be made available for the helmet bowls in view of a series production later on. 

The level of mental workload experienced by operators is a key element in the safety, reliability, and efficiency of complex sociotechnical systems (Gregoriades and Sutcliffe, 2007). Mental workload is a contentious area, and there has been great debate over how to define the concept. It is generally agreed that human operators possess a finite attentional capacity and that during task performance these atten-tional resources are allocated to component tasks. Workload is thus a function of the human operator s attentional capacity and the demand for resources imposed by the task. The level of mental workload represents the proportion of resources that are required to meet the task demands (Welford, 1978). Young and Stanton (2001) formally defined mental workload as follows The mental workload of a task represents the level of attentional resources required to meet both objective and subjective performance criteria, which may be mediated by task demands, external support, and past experience. Mental workload is therefore a multidimensional construct that is characterized by the task (e.g., complexity, demands) and the individual involved (e.g., skill, experience, training). 

Requirements are captured from stakeholders, users, and subject matter experts as early as possible in the Concept stage of the life cycle (Figure 2.1). These requirements must be analyzed, quantified, and verified, and must be able to be modified. Analysis is done to guarantee clarity, consistency, and traceability to lower-level requirements and across system parameters. Quantification allows costs, schedules, and resources to be identified for requirements. Verification of requirements allows the creation of test plans that will prove out safety cases and satisfy fail-safe... 

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