[SystemSafety] Degraded software performance [diverged from Fault, Failure and Reliability Again]

[Peter Bernard Ladkin]

I think that Drew has pointed out a number of phenomena which result in software changing
inadvertently and/or unobserved over time. Attributing the causes of those phenomena to "SW" or "HW"
is I suggest of secondary interest. What is of primary interest is that they do occur and as a
result software changes/can so change with the passage of time.

Suppose one wants to talk about that phenomenon. To me, "software degradation" seems a reasonable
term to use. Others may prefer to invent another term.

It's clear to me that the phenomena (maybe not all of them, but at least some) do occur/have
occurred and anyone preserving critical software for any length of time should take them into
account; devise detection and prophylaxis mechanisms and so on. Sort of like hardware, really.

PBL

Prof. Peter Bernard Ladkin, Faculty of Technology, University of Bielefeld, 33594 Bielefeld, Germany
Je suis Charlie
Tel+msg +49 (0)521 880 7319  www.rvs.uni-bielefeld.de