I'm not sure what you mean by CI. The Basic Engineering Design Data (BEDD) sheets are normally a very early step in establishing the design. Among other things, this document would provide the most basic and most important information such as site elevation, design weather conditions, utilities available, and many of the owner's preferences for sizing and for ways of doing things. This document should far preceed the early engineering work that is summarized in heat & material balances and schematically on Process Flow Diagrams (PFD's).