Modeling the object-oriented software process: OPEN and the unified process

A short introduction to software process modeling is presented, particularly object-oriented modeling. Two major industrial process models are discussed: the OPEN model and the Unified Process model. In more detail, the quality assurance in the Unified Process tool (formally called Objectory) is reviewed

UML to XML-Schema Transformation: a Case Study in Managing Alternative Model Transformations in MDA

In a Model Driven Architecture (MDA) software development process, models are\ud repeatedly transformed to other models in order to finally achieve a set of models with enough details to implement a system. Generally, there are multiple ways to transform one model into another model. Alternative target models differ in their quality properties and the selection of a particular model is determined on the basis of specific requirements. Software engineers must be able to identify, compare and select the appropriate transformations within the given set of requirements. The current transformation languages used for describing and executing model transformations only provide means to specify the transformations but do not help to identify and select from the alternative transformations. In this paper we propose a process and a set of techniques for constructing a transformation space for a given transformation problem. The process uses a source model, its meta-model and the meta-model of the target as input and generates a transformation space. Every element in that space represents a transformation that produces a result that is an instance of the target meta-model. The requirements that must be fulfilled by the result are captured and represented in a quality model. We explain our approach using an illustrative example for transforming a platform independent model expressed in UML into platform specific models that represent XML schemas. A particular quality model of extensibility is presented in the paper

Software measurement and functional programming

Software metrics have been investigated for the assessment of programs writ-ten in a functional programming language. The external attribute of programs considered in this thesis is their comprehensibility to novice programmers. This attribute has been operationalized in a number of experiments. The in-ternal attribute of software which is examined is the structure. Two models for the structure of software have been employed: callgraphs and flowgraphs. The proposed control-flow model captures the operational semantics of function definitions. The objective measurement of the attributes has been supported by tools. The validation of structure metrics has been addressed in certain ex-periments for programming-in-the-small. The structure of type expressions in functional programs has been analysed in a case study. A simple framework for software metrication proved to be useful. The validation of metrics has been linked with axioms from the representational measurement theory. The control-flow model for functional programs showed its value in the set-up of an experiment regarding the influence of the structure on the comprehensibility. A programming style rule on the use of guards in function definitions has been validated by the findings in this experiment

Disentangling Crosscutting in AOSD: A Conceptual Framework

Crosscutting is usually described in terms of scattering and tangling. However, the distinction between these three concepts is vague, sometimes leading to ambiguous statements and confusion. We propose a conceptual framework for crosscutting. Crosscutting is clearly distinguished from scattering and tangling. The definitions of these concepts are formalized and visualized with matrices and matrix operations. We discuss the relation between the concepts crosscutting, decomposition and coupling

Semantics of trace relations in requirements models for consistency checking and inferencing

Requirements traceability is the ability to relate requirements back to stakeholders and forward to corresponding design artifacts, code, and test cases. Although considerable research has been devoted to relating requirements in both forward and backward directions, less attention has been paid to relating requirements with other requirements. Relations between requirements influence a number of activities during software development such as consistency checking and change management. In most approaches and tools, there is a lack of precise definition of requirements relations. In this respect, deficient results may be produced. In this paper, we aim at formal definitions of the relation types in order to enable reasoning about requirements relations. We give a requirements metamodel with commonly used relation types. The semantics of the relations is provided with a formalization in first-order logic. We use the formalization for consistency checking of relations and for inferring new relations. A tool has been built to support both reasoning activities. We illustrate our approach in an example which shows that the formal semantics of relation types enables new relations to be inferred and contradicting relations in requirements documents to be determined. The application of requirements reasoning based on formal semantics resolves many of the deficiencies observed in other approaches. Our tool supports better understanding of dependencies between requirements

Teaching functional programming to first-year students

In the period 1986-1991, experiments have been carried out with an introductory course in computer programming, based on functional programming. Due to thorough educational design and evaluation, a successful course has been developed. This has led to a revision of the computer programming education in the first year of the computer science curriculum at the University of Twente. This article describes the approach, the aim of the computer programming course, the outline and subject matter of the course and the evaluation. Educational research has been done to assess the quality of the course. Contents 1 Introduction 50 1.1 Motivation 50 1.2 The students 51 2 The computer programming course 51 2.1 Functional Programming 52 2.2 Imperative Programming 53 2.3 Programming techniques 53 2.4 Instructional material 54 3 Evaluations 55 3.1 Observations 55 3.2 Problems 56 3.3 Functional versus imperative programming 58 4 Programming project 60 4.1 Organisation 61 4.2 Railway information sys..

Change Impact Analysis for SysML Requirements Models based on Semantics of Trace Relations

Change impact analysis is one of the applications of requirements traceability in software engineering community. In this paper, we focus on requirements and requirements relations from traceability perspective. We provide formal definitions of the requirements relations in SysML for change impact analysis. Our approach aims at keeping the model synchronized with what stakeholders want to be modeled, and possibly implemented as well, which we called as the domain. The differences between the domain and model are defined as external inconsistencies. The inconsistencies are propagated for the whole model by using the formalization of relations, and mapped to proposed model changes. We provide tool support which is a plug-in of the commercial visual software modeler BluePrint

Experimental Evaluation of a Tool for Change Impact Prediction in Requirements Models: Design, Results and Lessons Learned

There are commercial tools like IBM Rational RequisitePro and DOORS that support semi-automatic change impact analysis for requirements. These tools capture the requirements relations and allow tracing the paths they form. In most of these tools, relation types do not say anything about the meaning of the relations except the direction. When a change is introduced to a requirement, the requirements engineer analyzes the impact of the change in related requirements. In case semantic information is missing to determine precisely how requirements are related to each other, the requirements engineer generally has to assume the worst case dependencies based on the available syntactic information only. We developed a tool that uses formal semantics of requirements relations to support change impact analysis and prediction in requirements models. The tool TRIC (Tool for Requirements Inferencing and Consistency checking) works on models that explicitly represent requirements and the relations among them with their formal semantics. In this paper we report on the evaluation of how TRIC improves the quality of change impact predictions. A quasiexperiment is systematically designed and executed to empirically validate the impact of TRIC. We conduct the quasi-experiment with 21 master’s degree students predicting change impact for five change scenarios in a real software requirements specification. The participants are assigned with Microsoft Excel, IBM RequisitePro or TRIC to perform change impact prediction for the change scenarios. It is hypothesized that using TRIC would positively impact the quality of change impact predictions. Two formal hypotheses are developed. As a result of the experiment, we are not able to reject the null hypotheses, and thus we are not able to show experimentally the effectiveness of our tool. In the paper we discuss reasons for the failure to reject the null hypotheses in the experiment