Another stream of research considers a Markov production
process (also referred to as an interrupted geometric yield process) based on an out-of-control behavior of a production
system. Earlier works in this area include Porteus (1986) and Rosenblatt and Lee (1986). Porteus
(1986) assumes that the production process can go out-of-control every time an item is produced
leading to imperfect quality from that point further while Rosenblatt and Lee (1986) consider an
economic production quantity setting with a time until the process goes out-of-control which is
exponentially distributed. In a recent paper, Freimer et al. (2006) extend on Rosenblatt and Lee
(1986) by considering that the fraction of items produced is a general increasing function of time.
In another recent paper, Maddah et al. (2010a) expand the applicability of Porteus’ (1986) model,
by allowing imperfect quality items to be removed from inventory at the end
of a lot production.