An Empirical Study of a Software Maintenance Process

This paper describes how a process support tool is used to collect metrics about a major upgrade to our own electronic retail system. An incremental prototyping lifecycle is adopted in which each increment is categorised by an effort type and a project component. Effort types are Acquire, Build, Comprehend and Design and span all phases of development. Project components include data models and process models expressed in an OO modelling language and process algebra respectively as well as C++ classes and function templates and build components including source files and data files. This categorisation is independent of incremental prototyping and equally applicable to other software lifecycles. The process support tool (PWI) is responsible for ensuring the consistency between the models and the C++ source. It also supports the interaction between multiple developers and multiple metric-collectors. The first two releases of the retailing software are available for ftp from oracle.ecs.soton.ac.uk in directory pub/peter. Readers are invited to use the software and apply their own metrics as appropriate. We would be interested to correspond with anyone who does so

The Rodin Formal Modelling Tool

We present a software tool, the Rodin tool, for formal modelling in Event-B. Event-B is a notation and method developed from the B-Method and is intended to be used with an incremental style of modelling. The idea of incremental modelling has been taken from programming: modern programming languages come with integrated development environments that make it easy to modify and improve programs. The Rodin tool provides such an environment for Event-B. The two main characteristics of the Rodin tool are its ease of use and its extensibility. The tool focuses on modelling. It is easy to modify models and try out variations of a model. The tool can also be extended easily. This will make it possible to adapt the tool specific needs. So the tool can be adapted to fit into existing development processes instead demanding the opposite. We believe that these two characteristics are major points for industrial uptake

Approaches to the "fuzzy front end" of innovation

In new product development (NPD) unacceptably high failure rates have often been related to insufficiencies during the early development phases. Nevertheless, only little effort is devoted to the early phases, in theory as well as in practice, and managers often indicate the front end as being one of the greatest weaknesses in product innovation. Therefore, it is surprising that only little research has treated the so called fuzzy front end of innovation. In this paper we discuss if process models lead to success in the early development phases. Therefore, the discussion about process models for the whole innovation process is briefly summarized and findings applied to the fuzzy front end. Due to high uncertainties with a wide range between different innovations in the early phases, process models are found to lead to success for incremental innovations with low market and technological uncertainty only. For innovations with a high market and/or technological uncertainty, a learning-based approach is suggested. --breakthrough innovation,fuzzy front end,innovation management,innovation process,new product development,stage-gate process

Analytical and Numerical Solution of a Poisson RBC model

This paper analyses a RBC model in continuous time featuring deterministic incremental development of technology and stochastic fundamental inventions arriving according to a Poisson process. Other than in standard RBC models, shocks are uncorrelated, irregular and rather seldom. In two special cases analytical solutions are presented. In the general case a delay differential equation (DDE) has to be solved. Standard numerical solution methods fail, because the steady state is path dependent. A new solution based on a modified method of steps for DDEs provides not only approximations but also upper and lower bounds for optimal consumption path and steady state. --Business cycle models with poisson shocks,RBC models in continuous time,Delay differential equations

Modelling and analysing user views of telecommunications services

User views of calls are modelled by behaviour trees, which are synchronised to form a network of users. High level presentations of the models are given using process algebra and an explicit theory of features, including precedences. These precedences abstractly encapsulate the possible state spaces which result from different combinations of features. The high level presentation supports incremental development of features and testing and experimentation through animation. Interactions which are not detected during the experimentation phase may be found through static analysis of the high level presentation, through dynamic analysis of the under-lying low level transition system, and through verification of temporal properties through model-checking. In each case, interactions are resolved through manipulation of the feature precedences

Towards Consistency Management for a Business-Driven Development of SOA

The usage of the Service Oriented Architecture (SOA) along with the Business Process Management has emerged as a valuable solution for the complex (business process driven) system engineering. With a Model Driven Engineering where the business process models drive the supporting service component architectures, less effort is gone into the Business/IT alignment during the initial development activities, and the IT developers can rapidly proceed with the SOA implementation. However, the difference between the design principles of the emerging domainspecific languages imposes serious challenges in the following re-design phases. Moreover, enabling evolutions on the business process models while keeping them synchronized with the underlying software architecture models is of high relevance to the key elements of any Business Driven Development (BDD). Given a business process update, this paper introduces an incremental model transformation approach that propagates this update to the related service component configurations. It, therefore, supports the change propagation among heterogenous domainspecific languages, e.g., the BPMN and the SCA. As a major contribution, our approach makes model transformation more tractable to reconfigure system architecture without disrupting its structural consistency. We propose a synchronizer that provides the BPMN-to-SCA model synchronization with the help of the conditional graph rewriting

Evolutionary Models in Software Engineering

Software development life cycle models play a vital role in developing a software application. This research deals with such advanced models which are the evolutionary models namely: incremental model, and spiral model. Both these models have their own advantages and disadvantages as well. The main objective of this research paper is to represent the two evolutionary modelsrsquo features and limitations