A new testability model for better design and lower cost in equipment scheme phase

Testability evaluation is very critical to the scheme design phase of complex electronic equipment. Current methods for the testability modeling and evaluation require too much information, so they are very difficult to apply in the scheme design phase. Aiming at the features of complex electronic equipment, this paper establishes a new testability model based on the information achievable during the scheme design phase, to describe the correlated complexity between the out-of-tolerance of equipment index and the components of equipment. Based on this model, this paper presents a BIT optimal design algorithm with the target of reducing BIT design cost, and provides the testability design and evaluation process for the scheme design phase.