Temporality and the Analysis of Policy Processes

This chapter discusses the “historical turn” in the policy sciences and why it has occurred. It evaluates four general models of historical change processes that are commonly applied in policy analyses: stochastic, historical narrative, path dependency, and process sequencing. The chapter sets out the origins and elements of each model and assesses the merits and evidence for each in the analysis of public policymaking. The chapter suggests more work needs to be done examining the assumptions and presuppositions of each model before it can be concluded that any represents the general case for all policy processes. Neither the irreversible linear reality assumed by narrative models, nor the random and chaotic world assumed by stochastic models, nor the contingent turning points and irreversible trajectories required of the path dependency model are found very often in policymaking. Hence, the chapter agues these models are likely to be less significant than process-sequencing ones in describing the overall pattern of policy dynamics and temporality.

Design of Cloud-Based CAPP System to Aid Process Planning for Sheet Metal Products

In the design of new products, it is usual for different planners to specify different processing routes for the same part, which do not always incorporate the optimal solution to the problem. Computerization of process planning has evolved as a solution to speed up planning for new products. The essence of the chapter is to explore machine capabilities, parameters, and constrains inherent in sheet metal forming processes and then illustrate CAPP software design for process sequencing for new products to support standardisation of production routes. The verification of the designed CAPP system has realised significant savings of 40% reduction in process planning effort, 5% in material, 15% in scrap and 10% in tooling. In order to design the cloud-based CAPP system, data was gathered on the machinery capabilities for the sheet metal operations in a case study company that manufactures sheet metal accessories for the construction industry. A computer-based system was developed to store the machinery tool capabilities and their functional parameters and to facilitate sharing of information across the system modules. Autodesk Inventor® was used as the source of input for the CAD models into the system. Visual Basic.NET programming language was used to design a module for feature recognition (FR) to capture characteristics from a CAD model drawing of the new sheet metal product. A module was then developed to sequence the process operations for the CAD model based on the part features. The process sequencing system helps designers and process planners to link the new model design with the production path, the tools, and equipment required in order to improve their design and planning in the early stages of the product life cycle.