Spacecraft anomalies due to radiation effects on electronic devices have been known since the very beginning of the space era. Today they represent a major part of on-board anomalies, mission outages, and unexpected workload on ground controllers of operational systems. This text will first describe a few known cases of cumulative or transient effects in Earth or planetary environments. Then, it will discuss investigation methodology, and issues such as the statistical aspects of probabilistic anomalies in the assessment of cause to effects relationships, and the necessity of multi-field experts in group root cause analysis, from radiation effects, to satellite fault determination, to identification and reconfiguration strategy. A focus on some practical cases of anomaly analyses will be made.