PSI - Issue 22

Jerzy STANIK et al. / Procedia Structural Integrity 22 (2019) 334–344 "Author name" / Structural Integrity Procedia 00 (2019) 000 – 000

336

3

– set of system relations,

– usefulness of engineering infrastructure. Engineering infrastructures must be characterized by specific utility properties that determine, among others, such attributes as:  functional, information, organizational and engineering integrity of the systems,  minimum redundancy of processes, information and functions,  interoperability of systems,  adaptability to functional and structural changes,  security and reliability. We assume that usefulness, as the superior feature of engineering infrastructure, is a complex function of individual praxeological properties or features (Ficoń, 2011): = ( ; = 1,2, … ) (2) where: – the i-th usefulness feature of engineering infrastructure, – number of emphasized praxeological features of the engineering infrastructure. The subject of further analysis will be the selected, particular features of usefulness, which are the functional security and functional reliability, achieved while simultaneously meeting the remaining features/properties of the formula (2), therefore: ⊃ ̌ = ( , ). (3) Technical infrastructures are used by various economic entities in various ways, depending on the nature of the operations performed and the type of infrastructure-specific equipment. Bearing in mind the specific IT properties, that is:  dynamic broadening of the range of tasks and services provided according to the actual needs,  occurrence of variables and complicated situations in the emergence of various types of IT hazards and vulnerabilities,  occurrence of emergency situations due to damages,  lack of systems supporting reliability and functional safety, defined by applicable standards,  lack of appropriate mechanisms to control current IT usefulness features, The basic distinguishing mark of IT is also the obligation to maintain the required level of current reliability, functional safety as well as an acceptable level of risk. IT. Required levels of current functional reliability, functional security and risk can be achieved by taking appropriate control decisions that initiate the generation of appropriate functional configurations or safety configurations. The ability to take control decisions determines the existence of a specific subsystem of controlling the utility properties and security attributes, that are components of IT usefulness (Stanik, 1987). The subject of further analysis will also be a specific attribute of IT utility, which is the risk ( ℛ ) , which should be managed throughout the lifecycle of engineering infrastructure while meeting the properties of formula (3). Graphic illustration of the IT, from the point of view of controlling its current operational properties, security and maintenance of the current acceptable level of risk is presented in Figure 1.