Censored Observations
In general, censored observations arise whenever the dependent variable of interest represents the time to a terminal event, and the duration of the study is limited in time. Censored observations can occur in a number of different areas of research. For example, in the social sciences you can study the "survival" of marriages, high school drop-out rates (time to drop-out), turnover in organizations, and other events. In each case, by the end of the study period, some subjects could be married, some dropped out, or are still working at the same company; thus, those subjects represent censored observations.
In economics you can study the "survival" of new businesses or the "survival" times of products such as automobiles. In quality control research, it is common practice to study the "survival" of parts under stress (failure time analysis).