[2] Lewis' PhD thesis Bias Optimality in a Two-Class Nonstationary Queueing System[4] at Georgia Tech was advised by Robert E.
[2] Lewis founded the Institute for Operations Research and the Management Sciences (INFORMS) Minority Issues Forum in 2001 and served as its first president.
[16] Lewis served as principal investigator on the Cornell University Engineering Success Program to increase the participation of underrepresented minority and first-generation college students.
[19] He studied the dynamic control and optimal resource allocation of service systems, such as call centers, through "upgrades, reneging, and retrials" (for example after market segmentation).
[20] Lewis also develops methods for optimization of Markov decision processes to study problems such as inventory control and revenue management.