Are your sequences state based? Is there a finite set of conditions that drives your control sequences? If not, you may be missing out on one of the most intuitive ways to write control sequences.
State based sequencing uses conditional statements to drive sequences within a control system. For example, have you ever been to a site that is economizing when the mechanical cooling is on and the outdoor enthalpy is higher than the return enthalpy? This is a perfect example of a non-state based sequence. State based sequences look at a variety of external conditions and internal states to drive the sequencing of equipment within the control system.