Claudia S. Frydman

Tool support for the Test Template Framework

This paper describes tool support that has been implemented for the Test Template Framework (TTF). The TTF is a model‐based testing (MBT) method that is especially well suited for unit testing from Z specifications. Although the TTF is a sound MBT method and it has been widely referenced since its first publication, attention in recent years has decayed. In fact, some have argued that generating abstract test cases following the TTF is a manual task requiring its users to perform complex predicate manipulations. This paper shows that these observations are dubious by describing Fastest, a tool that implements solutions for all these issues and, according to many experiments, produces abstract test cases for more than 80% of the satisfiable test specifications. Furthermore, it is claimed that Fastest fulfils the needs of the Z user community regarding MBT tools, which is supported with a range of case studies. Copyright

A language for test case refinement in the test template framework

Model-based testing (MBT) generates test cases by analysing a formal model of the system under test (SUT). In many MBT methods, these test cases are too abstract to be executed. Therefore, an executable representation of them is necessary to test the SUT. So far, the MBT community has focused on methods that automate the generation of test cases, but less has been done in making them executable. In this paper we propose a language to specify rules that can be automatically applied to produce an executable representation of test cases generated by the Test Template Framework (TTF), a MBT method for the Z notation.

A semantic support to improve the collaborative control of manufacturing processes in industries

This paper put forwards how to improve the collaborative work of company engineers for the control of a manufacturing process. Sharing and using same manufacturing information in industries -such as control indicators- is necessary to efficiently ensure the control task. However, the generalization of Commercial Off-The-Shelf (COTS) systems in manufacturing companies to get such indicators has rapidly entailed the increase of the quantity of the digital resources, where a resource represents manufacturing data presented in specific formats. Retrieving such resources may become impossible without a semantic support. Our solution provides a semantic framework to enhance the retrieval of manufacturing information through the use of a business ontology and a domain-specific dictionary. The specificity of this business semantics is that it brings the resources closer to the business needs on one hand, and it unifies the business vocabulary in the company on other hand.

Applying the Test Template Framework to Aerospace Software

We have applied Fastest, an implementation of the Test Template Framework, to five real case studies of aerospace software. This involved the formalization in the Z notation of nontrivial parts of each system. One of these models, for instance, formalizes a significant portion of the ECSS-E-70-41A aerospace standard. The models were then fed into Fastest, which automatically generated detailed functional abstract test cases. Since these test cases are independent of any implementation, they can be used to test any of them. Furthermore, we were able to semi-automatically translate them into English so they can be used by domain experts performing independent validation and verification activities.

A Family of Simulation Criteria to Guide DEVS Models Validation Rigorously, Systematically and Semi-Automatically

Abstract The most common method to validate a DEVS model against the requirements is to simulate it several times under different conditions, with some simulation tool. The behavior of the model is compared with what the system is supposed to do. The number of different scenarios to simulate is usually infinite, therefore, selecting them becomes a crucial task. This selection, actually, is made following the experience or intuition of an engineer. Here we present a family of criteria to conduct DEVS model simulations in a disciplined way and covering the most significant simulations to increase the confidence on the model. This is achieved by analyzing the mathematical representation of the DEVS model and, thus, part of the validation process can be automatized.

Applying SMT Solvers to the Test Template Framework

The Test Template Framework (TTF) is a model-based testing method for the Z notation. In the TTF,test cases are generated from test specifications, which are predicates written in Z. In turn, the Znotation is based on first-order logic with equality and Zermelo-Fraenkel set theory. In this way, atest case is a witness satisfying a formula in that theory. Satisfiability Modulo Theory (SMT) solversare software tools that decide the satisfiability of arbitrary formulas in a large number of built-inlogical theories and their combination. In this paper, we present the first results of applying twoSMT solvers, Yices and CVC3, as the engines to find test cases from TTF’s test specifications. Indoing so, shallow embeddings of a significant portion of the Z notation into the input languages ofYices and CVC3 are provided, given that they do not directly support Zermelo-Fraenkel set theoryas defined in Z. Finally, the results of applying these embeddings to a number of test specificationsof eight cases studies are analysed.

Extending the test template framework to deal with axiomatic descriptions, quantifiers and set comprehensions

The Test Template Framework (TTF) is a method for model-based testing (MBT) from Z specifications. Although the TTF covers many features of the Z notation, it does not explain how to deal with axiomatic descriptions, quantifiers and set comprehensions. In this paper we extend the TTF so it can process specifications including these features. The techniques presented here may be useful for other MBT methods for the Z notation or for other notations such as Alloy and B, since they use similar mathematical theories.

CML-DEVS: A specification language for DEVS conceptual models

Abstract DEVS models are widely used in the research community, in the industry and even in military or defense departments. Therefore, several software tools exist for modeling and simulating these models. However, each of these tools has its specific input language and a DEVS model described within a particular framework cannot be simulated by a different one. Moreover, the practitioners willing to use one of these tools must have non-trivial programming skills or must ask to a programmer to translate their models into the language of the desired tool. In this paper, we present CML-DEVS, a language that allows the conceptual, abstract or mathematical representation of DEVS models, in terms of mathematical and logical expressions without involving programming issues. Models described with CML-DEVS can be automatically translated (i.e. compiled) into the input language of different modeling and simulation tools. We also present a set of rules to translate CML-DEVS models into models that can be simulated with well-known DEVS frameworks such as DEVS-Suite and PowerDEVS. These rules allow the implementation of a multi-target compiler.

Complementarity between simulation and formal verification transformation of PROMELA models into FDDEVS models: Application to a case study

Discrete Event system Specification (DEVS) is a simple comprehensive way to describe complex discrete-event systems in a hierarchical way. Few years ago, Finite and Deterministic DEVS (FDDEVS) was introduced to support verification analysis of a subclass of DEVS problems, in the same way as formal methods. This paper presents guidelines to transform behavioral models used in formal methods like critical sections, especially described in PROMELA in this case, into FDDEVS models, and shows the benefits of such a transformation.

A Method for Improving the Verification and Validation of Systems by the Combined Use of Simulation and Formal Methods

Verification and Validation (V&V) of Systems is an important process in the development of systems, in order to ensure that they are reliable and operational. Among methods of V&V, there are two that seem to be opposite to each other: simulation, which is empirical, and formal verification, which is comprehensive. Moreover, simulation and formal verification propose many different formalisms, increasing the gap between them. But, jointly used, these two powerful tools allow making a more efficient verification, increasing the confidence we can put in the verified systems. The main problem is how we can combine their use and how we can reduce the gap created by the nature of both of them. This paper presents guidelines and a general approach in order to use simulation, and especially discrete-event simulation, on a model specified in a verifiable formal language.