The environments appropriate to each operating or dormant phase of use must be determined because device failure rates vary according to the environment. Note that the term “environment” is used here in its broadest sense to mean qualitative operational locations (e.g., ship storage, air carriage, etc.) rather than detailed quantitative physical or climatic conditions (e.g., temperature 20°C, humidity 90%, etc.). The environmental categories are described in Table A-57 in Appendix A, Data Tables.