Technology sequence analysis (TSA)

An analysis method that involves the statistical combination of estimates of the time required to achieve intermediate technological steps toward a final technological, policy, or systems goal. TSA is useful in forecasting the range of dates by which a final objective could be achieved and the timing of intermediate technologies on which a system is dependent. Some TSA networks have involved thousands of "nodes" or intermediate steps. Networks of this size need efficient software and sophisticated databases. The technique begins with the construction of a network that illustrates the flow of sequential and interlocking technological or policy developments. Since such networks involve many facets of expertise, interviews with experts are usually used to determine the initial layout of the network. In these interviews, experts are asked not only to perfect the network, but also to provide judgments about the time or costs involved in progressing from one step to another, and judgments about timing and cost probabilities are collected.The underlying analysis involves the statistical combination of estimates of the time (or cost) required to achieve intermediate technological steps. TSA networks attempt to indicate all possible alternative technologies. In a Boolean sense, these are "or" paths. When any downstream achievement requires the simultaneous achievement of several prior technologies, the TSA solution requires that they all be present before the next step is possible. These are the Boolean "and" paths. The figure below illustrates both kinds of paths. The network of technologies might appear, in part, as follows:

This robot harvester illustration arrays five subsystems: (1) guidance, (2) position sensing, (3) ripeness sensing, (4) cleaning, and (5) packaging. This is a Boolean "and" node; that is, all five subsystems must be present for the robot to achieve the configuration envisioned.