Design and test-the next problems

Summary form only given. Over the past few years, the terms `design for test´ and `design to test´ have gradually been displaced by the term `design and test´. This change reflects the growing realization that test and design activities cannot easily be separated, but must be managed as part of a concurrent engineering process. The management of design and test starts with the realization that the test and maintenance requirements for different classes of products differ dramatically. The design team must understand what the test and maintenance policy for the products will be, and understand the implications of that policy on the pieces that make up the product. For large systems, the testability goals will propagate through the hierarchy of the designed pieces. This can be summarized as the need to design testable systems, from testable modules; testable modules from testable boards; testable boards from testable chips; and testable chips from testable cells. Furthermore, the test data from each level of the hierarchy needs to be reusable at the next larger level with straightforward processing, together with simple preparation of the test and diagnostic data specific to the new level