In Group Technology (GT) literature, there exist many algorithms for cell formation. All these algorithms assume that the conversion of job shop to cellular manufacturing (CM) is performed comprehensively rather than incrementally. In other words, all the academic studies done so far look at CM in terms of total number of products to be made and the total number of machines or machine types available (or needed), and try to plan a conversion of the entire shop into cells, possibly keeping a remainder cell. But planning and implementation of most cell conversions in industry are incremental (or sequential) ones, not comprehensive. To address this issue, incremental cell formation problem is addressed with an objective of minimization of total work content. The first step in incremental cell formation is the formation of pilot cell. In this paper a mathematical model for pilot cell formation is developed. Two heuristics are proposed for solving this problem and their performance is tested over several data sets.