Therefore, the type of technology fosters the structure required to coordinate and accomplish tasks. Perrow focused his research “more on the non routine aspects of technology than Woodward and Thompson” by studying difficulties that are not easily predictable or require more knowledge (Jones, 2010). Perrow used task variability and task analyzability to show how tasks can be more difficult than others and how this affects structure (Jones, 2010). He produced a classification system using these concepts assuming that the kind of technology being used establishes an organization's effective and efficient structure (Proven Models, 2010). Task variability is the number of unexpected occurences that a worker encounters in a day and task analyzability describes the amount of information required to solve a problem (Jones, 2010). Most organizations “have multiple technologies that operate interdependently”, and Perrow concluded that technology is a determinant of “uncertainty in organizations” (Proven Models, 2010). The three models described although based on the same principle have many differences in theory. Thompson’s studies included manufacturing and service-oriented organizations assuming that the type of technology determined the most effective structure (Proven Models, 2010). Thompson showed the importance of the environment in