70,995 research outputs found
A review of information flow diagrammatic models for product-service systems
A product-service system (PSS) is a combination of products and services to
create value for both customers and manufacturers. Modelling a PSS based on
function orientation offers a useful way to distinguish system inputs and
outputs with regards to how data are consumed and information is used, i.e.
information flow. This article presents a review of diagrammatic information
flow tools, which are designed to describe a system through its functions. The
origin, concept and applications of these tools are investigated, followed by an
analysis of information flow modelling with regards to key PSS properties. A
case study of selection laser melting technology implemented as PSS will then be
used to show the application of information flow modelling for PSS design. A
discussion based on the usefulness of the tools in modelling the key elements of
PSS and possible future research directions are also presented
Designing Reusable Systems that Can Handle Change - Description-Driven Systems : Revisiting Object-Oriented Principles
In the age of the Cloud and so-called Big Data systems must be increasingly
flexible, reconfigurable and adaptable to change in addition to being developed
rapidly. As a consequence, designing systems to cater for evolution is becoming
critical to their success. To be able to cope with change, systems must have
the capability of reuse and the ability to adapt as and when necessary to
changes in requirements. Allowing systems to be self-describing is one way to
facilitate this. To address the issues of reuse in designing evolvable systems,
this paper proposes a so-called description-driven approach to systems design.
This approach enables new versions of data structures and processes to be
created alongside the old, thereby providing a history of changes to the
underlying data models and enabling the capture of provenance data. The
efficacy of the description-driven approach is exemplified by the CRISTAL
project. CRISTAL is based on description-driven design principles; it uses
versions of stored descriptions to define various versions of data which can be
stored in diverse forms. This paper discusses the need for capturing holistic
system description when modelling large-scale distributed systems.Comment: 8 pages, 1 figure and 1 table. Accepted by the 9th Int Conf on the
Evaluation of Novel Approaches to Software Engineering (ENASE'14). Lisbon,
Portugal. April 201
Real Option Valuation of a Portfolio of Oil Projects
Various methodologies exist for valuing companies and their projects. We address the problem of valuing a portfolio of projects within companies that have infrequent, large and volatile cash flows. Examples of this type of company exist in oil exploration and development and we will use this example to illustrate our analysis throughout the thesis. The theoretical interest in this problem lies in modeling the sources of risk in the projects and their different interactions within each project. Initially we look at the advantages of real options analysis and compare this approach with more traditional valuation methods, highlighting strengths and weaknesses ofeach approach in the light ofthe thesis problem. We give the background to the stages in an oil exploration and development project and identify the main common sources of risk, for example commodity prices. We discuss the appropriate representation for oil prices; in short, do oil prices behave more like equities or more like interest rates? The appropriate representation is used to model oil price as a source ofrisk. A real option valuation model based on market uncertainty (in the form of oil price risk) and geological uncertainty (reserve volume uncertainty) is presented and tested for two different oil projects. Finally, a methodology to measure the inter-relationship between oil price and other sources of risk such as interest rates is proposed using copula methods.Imperial Users onl
Deferred Action: Theoretical model of process architecture design for emergent business processes
E-Business modelling and ebusiness systems development assumes fixed company resources,
structures, and business processes. Empirical and theoretical evidence suggests that company resources
and structures are emergent rather than fixed. Planning business activity in emergent contexts requires
flexible ebusiness models based on better management theories and models . This paper builds and
proposes a theoretical model of ebusiness systems capable of catering for emergent factors that affect
business processes. Drawing on development of theories of the âaction and designâclass the Theory of
Deferred Action is invoked as the base theory for the theoretical model. A theoretical model of flexible
process architecture is presented by identifying its core components and their relationships, and then
illustrated with exemplar flexible process architectures capable of responding to emergent factors.
Managerial implications of the model are considered and the modelâs generic applicability is discussed
Identifying and Modelling Complex Workflow Requirements in Web Applications
Workflow plays a major role in nowadays business and therefore its
requirement elicitation must be accurate and clear for achieving the solution
closest to businessâs needs. Due to Web applications popularity, the Web is becoming
the standard platform for implementing business workflows. In this
context, Web applications and their workflows must be adapted to market demands
in such a way that time and effort are minimize. As they get more popular,
they must give support to different functional requirements but also they
contain tangled and scattered behaviour. In this work we present a model-driven
approach for modelling workflows using a Domain Specific Language for Web
application requirement called WebSpec. We present an extension to WebSpec
based on Pattern Specifications for modelling crosscutting workflow requirements
identifying tangled and scattered behaviour and reducing inconsistencies
early in the cycle
The impact of tax uncertainty on irreversible investment
Traditional models of capital budgeting including taxes are based on deterministic tax rates and tax bases. In reality, however, there are multiple sources of tax uncertainty. Tax reforms induce frequent changes in both tax rates and tax bases, making future taxation of investments a stochastic process. Fiscal authorities and tax courts create additional tax uncertainty by interpreting current tax laws differently. Apart from fiscal tax uncertainty, there is modelspecific tax uncertainty, because investors use simplified models for computing an investment project's tax base and anticipate the actual tax base incorrectly. I analyze the effects of stochastic taxation on investment behaviour in a real options model. The potential investor holds an option to invest in an irreversible project with stochastic cash flows. To cover the combined effects of tax base and tax rate uncertainty, the investment's tax payment is modelled as a stochastic process that may be correlated with the project's cash flows. I show that increased uncertainty of tax payments has an ambiguous impact on investment timing. Thus, the popular view that tax uncertainty depresses real investment can be rejected. For low tax uncertainty, high cash flow uncertainty and high correlation of cash flows and tax payment, increased tax uncertainty may even accelerate investment. A higher expected tax payment delays investment. Surprisingly, a higher tax rate on interest income affects investment timing ambiguously. --
Knowing A Few Rules Doesnât Mean You Can Play the Game : The Limits of âBest Practiceâ in Enterprise Systems.
We examine the common claim that "best practices" are encompassed and represented in Enterprise Systems (ES). We suggest that an ES can at best only represent the ostensive and not the performative elements of work tasks. Thus, representation of best practice in an ES does not take practical action into account. This has two important implications. First, ostensive abstractions of best practice in an ES are a sparse and superficial representation of a "good" business process, at a specific moment in time. Second, the practical understanding required for performance is often ignored in the ostensive representation of best practice in the implementation of an ES. This constrains user and business adaptability. Inflexible coding of ostensive business tasks furthermore leads to rigidity where flexibility should be sought, to keep on top of the competition. Implications and directions for further research are discussed
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