Machine safety systems have evolved from strictly hardwired systems, where safety and standard logic were separate, to the multifaceted spectrum of newer programmable systems with varying levels of cost, complexity, and wiring methods. When designing safety into machinery, engineers must verify compliance with today’s more-stringent standards and determine how safety will interplay with productivity to keep downtime to a minimum. Engineers also should consider how flexible and scalable a safety system will be with evolving operations.