Asma Sellami

A framework for the design and verification of software measurement methods

At the core of any engineering discipline is the use of measures, based on ISO standards or on widely recognized conventions, for the development and analysis of the artifacts produced by engineers. In the software domain, many alternatives have been proposed to measure the same attributes, but there is no consensus on a framework for how to analyze or choose among these measures. Furthermore, there is often not even a consensus on the characteristics of the attributes to be measured. In this paper, a framework is proposed for a software measurement life cycle with a particular focus on the design phase of a software measure. The framework includes definitions of the verification criteria that can be used to understand the stages of software measurement design. This framework also integrates the different perspectives of existing measurement approaches. In addition to inputs from the software measurement literature the framework integrates the concepts and vocabulary of metrology. This metrological approach provides a clear definition of the concepts, as well as the activities and products, related to measurement. The aim is to give an integrated view, involving the practical side and the theoretical side, as well as the basic underlying concepts of measurement.

Functional Size of Use Case Diagrams: A Fine-Grain Measurement

Software functional size (FS) prediction early in its lifecycle is vital for software project management. Such prediction requires the definition of software measures in terms of the specification and/or design language concepts. Within this context, several researchers have projected COSMIC functional size measures (FSM) onto various UML diagrams. However, these projections treated the diagrams separately despite their syntactic and semantic overlap within a model. In this paper, we present a fine-grain measurement for the UML use case diagram. Being a central diagram for models derived through the Unified Process, the use case diagram is implicitly related to all other diagrams. Thus, the detailed measurement of this diagram provides a reference measurement standard for other UML diagrams, e.g., the sequence and class diagrams.

A measurement method for sizing the structure of UML sequence diagrams

ContextThe COSMIC functional size measurement method on UML diagrams has been investigated as a means to estimate the software effort early in the software development life cycle. Like other functional size measurement methods, the COSMIC method takes into account the data movements in the UML sequence diagrams for example, but does not consider the data manipulations in the control structure. This paper explores software sizing at a finer level of granularity by taking into account the structural aspect of a sequence diagram in order to quantify its structural size. These functional and structural sizes can then be used as distinct independent variables to improve effort estimation models. ObjectiveThe objective is to design an improved measurement of the size of the UML sequence diagrams by taking into account the data manipulations represented by the structure of the sequence diagram, which will be referred to as their structural size. MethodWhile the design of COSMIC defines the functional size of a functional process at a high level of granularity (i.e. the data movements), the structural size of a sequence diagram is defined at a finer level of granularity: the size of the flow graph of their control structure described through the alt, opt and loop constructs. This new measurement method was designed by following the process recommended in Software Metrics and Software Metrology (Abran, 2010). ResultsThe size of sequence diagrams can now be measured from two perspectives, both functional and structural, and at different levels of granularity with distinct measurement units. ConclusionIt is now feasible to measure the size of functional requirements at two levels of granularity: at an abstract level, the software functional size can be measured in terms of COSMIC Function Point (CFP) units; and at a detailed level, the software structural size can be measured in terms of Control Structure Manipulation (CSM) units. These measures represent complementary aspects of software size and can be used as distinct independent variables to improve effort estimation models.

Quantitative Functional Change Impact Analysis in Activity Diagrams: A COSMIC-Based Approach

Change requests are inevitable in every phase of the Software Development Life Cycle (SDLC), and responding to a change request without jeopardizing the project success remains a challenge for software developers/managers. Expressing functional changes in terms of COSMIC Function Point units can be helpful in identifying changes leading to a potential impact on the software functional size; this latter can be used as a means to plan the project activities. This paper proposes to analyze the impact of functional changes on the size of UML activity diagrams, one artifact type produced early in the SDLC. The proposed analysis handles directly as well as indirectly affected elements in both modelling levels of the activity diagrams.

Automated COSMIC-Based Analysis and Consistency Verification of UML Activity and Component Diagrams

UML has been established as a de facto standard for modeling software. It offers a set of complementary diagram types used to document functional, dynamic and static views of a system. UML diagrams diversification and their multi-view representation can cause inconsistencies among the diagram types used to model the system during the different development phases. This paper presents an automated COSMIC-based approach for checking the consistency between the activity and component diagrams. First, it defines measurement procedures to determine the functional size of both diagrams. Secondly, it proposes a set of heuristics to ensure the consistency in terms of COSMICFSM. Third, it presents a tool for measuring the functional size of these diagrams, and then checking their consistency.

Evaluating Security in Web Application Design Using Functional and Structural Size Measurements

Because of software requirements play a critical role in software development projects, measuring the non-functional requirements as well as functional requirements is therefore not to be trifled with. Software security as a non-functional requirement is one of the most important quality characteristic that is recently added in the ISO 25010 quality models (previously defined as sub characteristics in ISO 9126). This characteristic must be evaluated cautiously and precisely during all the software life-cycle and especially early in the design phase. The purpose of this paper is early evaluating security in web application. To achieve this purpose, we propose to measure the quality attributes of authenticity through a combination of functional and structural size of the authenticity sequence diagram at the design phase. This combination of measurement can be used to identify the risk of violation of authenticity in web application design. An example of GeoNetwork web application is used to illustrate our proposed measurement for evaluating security as defined by ISO/IEC 25010.

Predicting the functional change status in UML activity diagram from the use case diagram

UML diagrams became a common part of software requirement documentation, implementation, etc. In particular, the Use Case Diagram (UCD) is considered as the de-facto standard for modelling the user requirements at an early phase of the Software Development Life Cycle (SDLC). Each use case can be detailed by an Activity Diagram (UAD). Because Functional Changes (FC) are inevitable during the SDLC, it is required to identify the FC status at different levels of granularity. In our previous work, we proposed an approach for measuring the functional size of a FC in the UAD using COSMIC method. In this paper, we propose to extend this approach by including the UCD. In addition, we predict the status of a FC in UAD from its use case. This approach is applied before the FC implementation. It allows a rapid and an approximate evaluation of how important the FC is and it helps designers/managers in decision-making to answer the FC request.

Identifying and localizing the inter-consistency errors among UML use cases and activity diagrams: An approach based on functional and structural size measurements

Because of their structural and semantic inter-dependency, UML diagrams describing a software product must be consistent to ensure the success of the development process. This inter-diagram consistency is often not easy to ensure considering the multi-views the diagrams cover, the different levels of abstraction they encode, and the different development phases during which they are produced. In this paper, we tackle the consistency problem between the functional and dynamic views in behavioral diagrams of software. We propose an approach to detect and localize inter-consistency errors among UML use cases and activity diagrams. This approach is composed of two phases: measurement phase (1) and controlling phase (2). This approach is illustrated and validated through a “Restaurant management system” case study. The proposed approach will help both software designers/developers and quality assurance/testing engineers identifying and localizing the causes of software errors at early phases (specification and design).

Analyzing Functional Changes in BPMN Models using COSMIC.

When performing functional requirements analysis, software developers need to understand the application domain to fulfil organizational needs. This is essential for making trade-off decisions and achieving the success of the software development project. An application domain is dealt within the modelling phase of the business process lifecycle. Assuming that functional changes are inevitable, we propose to use the standard COSMIC to evaluate these changes and provide indicators of change status in the business domain. Expressing functional changes in terms of COSMIC Function Point units can be helpful in identifying changes leading to potential impact on the business processs functional size. In addition, we propose a top-down decomposition approach to specify requirements and analyse change impact on BPMN models at different

Analyzing the Risk of Authenticity Violation Based on the Structural and Functional Sizes of UML Sequence Diagrams

Paying attention to authenticity, as a security requirement, in the early phases of the software life-cycle (such as requirement and-or design) can save project cost, time, and effort. However, in the ISO 25010 quality model which describes quality sub-characteristics, authenticity measures are not explicitly described, neither are they documented with sufficient details. This paper proposes a clear and precise way of measuring the “authenticity” sub-characteristic based on structural and functional size measurements. This combination can be used to identify the risk of authenticity violation in the design phase. An example of Facebook Web User Authentication is used to illustrate our proposed measurement.