Structured Test Methodology Research Articles

AgentTest: A specification language for agent-based system testing

AgentTest is a sublanguage of TTCN-3, aimed at specifying and testing agent-based systems. Its major strength is its unification and automation of abstract test suite generation and structured testing methodology for agent-based systems. AgentTest enables formal and strongly typed modelling of agent-based systems and their unit and agent testing. This paper introduces the syntax and semantics of AgentTest language and its modelling and testing methodology through the example of an agent-based weather system. AgentTest methodology is also complemented with an evolutionary testing methodology for test case generation based on a multi-objective genetic algorithm.

Statistical Path Selection for At-Speed Test

Process variations make at-speed testing significantly more difficult. They cause subtle delay changes that are distributed in contrast to the localized nature of a traditional fault model. Due to parametric variations, different paths can be critical in different parts of the process space, and the union of such paths must be tested to obtain good process space coverage. This paper proposes an integrated at-speed structural testing methodology, and develops a novel branch-and-bound algorithm that elegantly and efficiently solves the hitherto open problem of statistical path tracing. The resulting paths are used for at-speed structural testing. A new test quality metric is proposed, and paths which maximize this metric are selected. After chip timing has been performed, the path selection procedure is extremely efficient. Path selection for a multimillion gate chip design can be completed in a matter of seconds.

The construction of contextual def-use associations for object-oriented systems

This paper describes a program representation and algorithms for realizing a novel structural testing methodology that not only focuses on addressing the complex features of object-oriented languages, but also incorporates the structure of object-oriented software into the approach. The testing methodology is based on the construction of contextual def-use associations, which provide context to each definition and use of an object. Testing based on contextual def-use associations can provide increased test coverage by identifying multiple unique contextual def-use associations for the same context-free association. Such a testing methodology promotes more thorough and focused testing of the manipulation of objects in object-oriented programs. This paper presents a technique for the construction of contextual def-use associations, as well as detailed examples illustrating their construction, an analysis of the cost of constructing contextual def-use associations with this approach, and a description of a prototype testing tool that shows how the theoretical contributions of this work can be useful for structural test coverage.

Application of supply current testing to analogue circuits, towards a structural analogue test methodology

This paper describes work in progress towards the development, evaluation and validation of a structural, cost effective and quantifiable analog and mixed-signal test methodology, applicable in a production test environment and based on the application of supply current testing. To enable and support the measurements at first an analog supply current monitor was realised. The monitor offers a measurement range of 50 mA, a bandwidth of 1.5 MHz and a resolution better than 1 /spl mu/A. Subsequently the monitor was used to carry out measurements on a mixed-signal Asynchronous Digital Subscriber Line (ADSL) ASIC, to evaluate the feasibility of the methodology. As these initial measurements provided very interesting results, the experiments towards the validation and quantification of the test methodology are now being repeated on a larger scale. The results gathered so far show the potential of the approach to enhance test quality combined with test cost reduction.

Fault observability analysis of analog circuits in frequency domain

We study the testability of analog circuits in the frequency domain by introducing the analog fault observability concept. The proposed algorithm indicates the set of adequate test frequencies and test nodes to increase fault observability. This approach combines a structural testing methodology with functionality verification to increase the test effectiveness and consequently the design manufacturability and reliability. We analyze the case of single fault, double, and multiple faults. Concepts such as fault masking, fault dominance, fault equivalence, and non observable fault in analog circuits are defined and then used to evaluate testability. The theoretical aspect is based on the sensitivity approach.

Designing and implementing an architecture with boundary scan

A description is given of a standardized structured test methodology based on the boundary-scan proposal from the Joint Test Action Group (JTAG), which is now IEEE proposed standard P1149.1. Boundary scan does not address testability at the IC level, primarily because there is no standard for designing built-in self-testing (BIST) circuits. An architecture called the hierarchical testable, or H-testable, architecture that is compatible with the JTAG boundary-scan standard for PCB testing and provides BIST at the IC level is presented. The two have been merged, ensuring testability of the hardware from the printed-circuit-board level down to integrated-circuit level. In addition, the architecture has built-in self-test at the IC level. The authors have implemented this design using a self-test compiler. >

Structural testing of programs

Program testing may be performed using either one of two approaches; structural or functional. This paper is concerned with the structural testing approach of programs. Given a listing of the program, the first step is to construct its flowgraph. The flowgraph usually contains a very large number of paths, owing to the program loops, so testing all the paths is impossible. A subset of these paths are chosen, according to one criterion or another. Then, a set of test data is generated which causes the selected paths to be traversed when the program runs. Finally, the program runs, using the generated test data, and the output is analysed to detect program errors. The paper discusses the problems involved and the methods used in each step of the above mentioned structural testing methodology.