Is Technological Trajectory Disruptive?

Abstract

Abstract: Christensen and Bower (1996) and Christensen (1997, 2003) discuss disruptive innovation by applying Dosi's concept of disruptive technological trajectories (Dosi, 1982). In the studies on performance of hard disk drives, Christensen uses and re-uses reprinted graph, in which time and performance are on the horizontal and vertical axes. However, careful examination of different publications shows a varying shape and vertical axis, raising doubts about its reliability. In fact, whether the technological trajectories look disruptive or sustaining depends on the unit on the vertical axis. To present the nature of technological trajectories, it would appear more appropriate to set the vertical axis to volumetric recording density for hard disk drives. Moreover, the technological trajectories of hard disk drives would not be disruptive, if the vertical axis was adjusted to reflect weights of hard disk drives or amounts of their electricity use. It is conceivable that Christensen came to this conclusion that the technological trajectories are disruptive before considering a more appropriate performance measure for them.Keywords: hard disk drive, disruptive technological trajectory, disruptive innovation, innovator's dilemma1. IntroductionNelson and Winter (1977) used natural trajectories1 to determine the direction of technological progress. Based on this, Dosi (1982) introduced the concept of technological trajectories. Further, Christensen and Bower (1996) make a distinction between trajectory-sustaining innovation and trajectory-disrupting (or trajectory-disruptive) radical innovation.2Dosi (1982) defines a technological trajectory as the pattern of problem solving activity, that is of progress, on the grounds of a technological paradigm (Dosi, 1982, p.152). These activities represent continuity or incremental innovation (Dosi, 1982, p. 158). For example, the technological change from a 14-inch removable disk pack to a 14-inch Winchester drive has a sustaining impact on an established trajectory of performance improvement (Christensen & Bower, 1996). In Figure 1,3 this can be seen as the switch from technology A to technology B.In general, a new technology consecutively replaces an old one. As technology A approaches a given level of maturity, the pace of its performance improvement decreases, causing a switch to technology B. Similarly, there is a switch from technology B to technology C and on to technology D. This is known as a continuous technological trajectory, illustrated by the red line in Figure 1, which is a locus of trajectory-sustaining technological change.2. Disruptive TrajectoryBy contrast, Dosi (1982) also suggests an extraordinary breakthrough as a result of radical innovation, a clear technological leap that is discontinuous on the upper side; whereas Christensen and Bower (1996) posit discontinuity on the lower side and that when one technological trajectory ends (e.g., Technology A in Figure 2), a trajectory of inferior technology with lower performance (e.g., Technology B in Figure 2) originates from below. Figure 2 clearly shows a disruptive trajectory for hard disk drives when product performance, measured in terms of storage capacity or disk size, deviated due to technological change, that is, from A (14 inch) to B (8 inch) to C (5.25 inch) to D (3.5 inch).Under normal circumstances, when there is a technological change from an existing technology to a new one with higher performance, such as the change from disk-pack drives to Winchester drives, the market reacts positively to it. This holds true whether the technological change is continuous or discontinuous (Dosi, 1982, referred to this type of discontinuity as upward compatibility), given that performance of the new technology is higher than the old one; if not, the product would not be marketable. Thus, this type of change should be trajectory sustaining.However, in the hard disk drive market, toy-like products with inferior performance gain a separate large market and are sold in that market rather than in the existing market. …