Utilizing a modular plant design has become an increasingly popular way for engineers to build and operate process plants. Modular designs use modular units that are purpose-built offsite before being shipped to the site where they will be used. Modular plants have several advantages over traditional methods of building a process plant, such as scalability, cost savings, environmental friendliness and better safety in place. But there are also potential drawbacks that should be reviewed carefully by any engineer considering this approach.