PSI - Issue 22

Jerzy STANIK et al. / Procedia Structural Integrity 22 (2019) 322–333 "Author name" / Structural Integrity Procedia 00 (2019) 000 – 000

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for example, the financial value of replacing one of the resources (or its part), cost of acquisition, configuring and installing new resources or restoring these from backups, the cost of suspended operations caused by the incident, before the service performed by the resource (e.g. process) will be restored, the effect of a breach of functional security or information security. 3.2. Potential of the hazard subsystem Potential Ω can be determined using the general formula of the below type: Ω = ( Ω , , ; u ∈ U IT ; z ∈ Z u IT ) → ℜ I +T where: Z u IT - set of hazards directly harming IT in relation to the u-th usefulness feature, , - the real potential of the z-th hazard in a hazard system posing a hazard with regard to the u-th usefulness feature. Should it not be possible to directly determine the real potential Ω , it can be determined based on the knowledge of the hypothetical potential Ω , using the below multiplicative formula: Ω , ∶ ℱ × Ω , → ℜ I +T ; (14) where: ℱ - effectiveness index from the z-th hazard in relation to the u-th usefulness feature, Ω , - the hypothetical hazard potential (destructive force) of the z-th hazard in a hazard system with regard to the u-th usefulness feature. If we could express all of the hypothetical potentials Ω u , P z in a certain normalized numerical space ℕ ∈ ℜ I +T , then the total hypothetical potential ( Ω ) in relation to the u ∈ U IT feature can be determined as a weighted additive function of partial potentials, that is: Ω = ∑ , Z̿ uIT =1 , , ; u ∈ U IT ; z ∈ Z u IT ) → ℕ , (15) where: , – weight factors of individual hazards that may generate loss of IT usefulness in relation to the u-th usefulness feature, Total real potential ( Ω ) can be determined as a weighted additive function of partial potentials, i.e.: Ω ∶ Γ × Ω → ℕ , (16) where: Γ – function of transformation of potential hazards into real ones in relation to the b-th usefulness feature. The real hazard potential component is a type of unit quality (destruction) indicator of the hazard system, which illustrates the quantitative level of hazards to the individual IT usefulness features. The total potential of real hazards represents the quantitative level of challenges that the IT safeguard system must cope with, and in particular its actual response potential identified with real capabilities to counteract the existing hazards. (13) 3.3. Potential of the safeguard subsystem Potential can be determined using the general formula of the below type: where: ZTO u IT - a set of security mechanisms (safeguards) of an engineering or organizational nature assigned to maintain the u-th usefulness feature, , - the real potential of the m-th safeguard in the safeguard system assigned to maintain the u-th usefulness feature. = ( , , ; u ∈ U IT ; m ∈ ZTO u IT ) → ℜ I +T (17)