This is a companion to last month’s “Art and Science of Point Selection” column. The sequence of operation (“sequence”) is the most important aspect of BAS design. BASs require extensive sequence programming by the installer to transform it from a pile of electronics into the brain of an HVAC operation. As with point selection, sequence writing: 1) Requires an “art and science” approach, and 2) Is an iterative process with the point selection. So this column won’t provide much detail about these aspects (revisit last month’s column, if necessary) but instead will focus on the key aspects unique to sequences.