An Improved VLSI Test Economics Analysis System - Laboratory for ...

1.1 Economic ModelsIn the economic models, the prot can be estimated by anumber of circuit parameters suchas the number of gates, nets, and I/Os, and the sequential depth, routing ratio, physicaldesign rule, netlist, layout, etc. However, not all of these circuit parameters are availablein early design cycle, therefore the circuit parameters of our models must be available oreasy to estimate early in the design phase. In our study, we propose a set of such circuitparameters. Besides, some models are developed to estimate the parameters if they can notbe obtained directly in the early design stage.The prot is equal to the revenue subtracted by cost. The revenue comes from market.Thus, a Market Life Model is proposed to estimate the revenue. This model use generalproduction life cycle model to gure out relation between revenue and time to market. Thetime to market will be estimated in the Time Model. Then, we can obtain the revenue ofthe project under consideration.Cost includes capital, labor and raw material. Capital is dened as long-term investmentsuch as land, buildings, machines and tools. Labor includes man-power and management.There are dierence between capital cost and the other two costs. The labor and raw materialcosts are purchased only for immediate or current use, but capital cost is generally purchasedfor use over a long period. Thus, the reasonable capital cost is the depreciation value duringthe current project. In our study, we propose three types of cost equation: one for labor andraw material cost and the other two for capital cost.Most of our cost equations are functions of the time. For example, the salary of designman-power is proportional to the design time and the cost of tester, and the cost of testeris estimated as the depreciation during the test execution time. Some of these time relatedparameters are hard to estimate directly. We propose a Time Model to estimate theseparameters.Cost Model is proposed to estimate total cost of a project. The project is divided intothree stages: design, manufacture and test. Our model estimate each stage cost hierarchically.Each stage cost continuously divided into more and more detail item cost, then theproposed three type cost equations are selected to model each item cost. Finally, all the item2