Deploying the 1B processor involved installing and retrofitting it in a live, fully operational 4ESS™ switch. The customer requirements for deploying the 1B processor were simple, clear, and stark: “flawless execution with no interruption to service.” To accomplish this, special bus switches were designed to allow peripheral units to be switched from the 1A to the 1B processor as part of the retrofit. The aggressive schedule called for installing the 1B processor in 134 AT&T switches in only 16 months. This paper describes the unique customer-supplier partnering approach used to meet the customer requirement of “flawless execution.” It also discusses the major leadership-based procedures used to improve processes and eliminate risks.