A Note on "Discrete Sequential Search with Group Activities"

This note comments on a paper published by Wagner and Davis ( Decision Sciences (2001), 32(4), 557–573 ) . These authors present an integer-programming model for the single-item discrete sequential search problem with group activities. Based on their experiments, they conjecture that the problem can be solved as a linear program. In this note, we provide a counterexample for which the optimal value of the linear program they propose is different from the optimal value of the integer-programming model, hence contradicting their conjecture for the specific linear program that they specify. To the best of our knowledge, the conjecture settled in this note was still an open question. [Submitted: April 18, 2012. Revised: June 11, 2012. Accepted: June 13, 2012.] Subject Areas: Discrete Sequential Search, Integer Programming, and Linear Programming.