Impact Analysis Approach Research Articles

Architecture-based change impact analysis in cross-disciplinary automated production systems

Maintaining an automated production system is a challenging task as it comprises artifacts from multiple disciplines – namely mechanical, electrical, and software engineering. As the artifacts mutually affect each other, even small modifications may cause extensive side effects. Consequently, estimating the maintenance effort for modifications in an automated production system precisely is time consuming and often nearly as complicated as implementing the modifications. In this paper, we present the KAMP4aPS approach for architecture-based change impact analysis in production automation. We propose metamodels to specify the various artifacts of the system and modifications to them, as well as algorithms and rules for change propagation analysis based on the models. We evaluate KAMP4aPS for three different change scenarios based on the established xPPU community case study on production automation. In the case study, we investigate different configurations of metamodels and change propagation rules. Evaluation results indicate the accuracy of change propagation for applying KAMP4aPS to the specific metamodel and rules.

Impact of capacity fluctuation on throughput performance for semiconductor wafer fabrication

• The impact of critical machines’ available time (AT) fluctuation, the level of AT%, and the loading of machine on semiconductor wafer fab's throughput performance have been studied. • A capacity impact analysis approach, based on an object-oriented wafer fab capacity planning and analysis simulation (CPAS) system, has been presented. • The simulation experiment shows that a fab's capacity performance is highly affected by the machines belonging to single machine-multiple layers (SM) machine group, and the level of AT% (i.e., not the AT fluctuation), the fab management staffs should put more attention on the “key” machines’ promised AT. • It is worthy to buy or rent one extra non-critical machine if it did have a serious continuous downtime periods (e.g., more that 7 days) occurred in one month under the situation of medium (e.g., 70%) to high scheduled loading situation. With the characteristics of high capital investment and complicated manufacturing processes, effectively planning and analyzing the available capacity is a crucial challenge in semiconductor industry. However, the fab management staffs usually believe that the ideal planned capacity , generated by static capacity planning approach, is too optimistic to achieve, in particular, many abnormal events (e.g., machine breakdown) occurring in fab are not reasonably considered. Therefore, this paper aims at proposing a capacity impact analysis (CIA) approach based on a reasonable capacity plan generated by an object-oriented capacity planning simulation system. As such it analyzes the impact of the identified critical available time (AT) fluctuation of machines, the level of AT%, and the loading of machine on overall capacity and output performance (e.g., wafer out, utilization, WIP) in a fab. The simulation experiment shows that a capacity performance is highly affected by the machines belonging to a single machine-multiple layers (SM) machine group, and the level of AT% (i.e., not the AT fluctuation). Therefore, fab management staff should put more attention on the promised AT or increasing the level of AT% of the “key” machines to maintain a high throughput.

Influence of soft tissue in the assessment of the primary fixation of acetabular cup implants using impact analyses

BackgroundThe acetabular cup (AC) implant primary stability is an important determinant for the success of cementless hip surgery but it remains difficult to assess the AC implant fixation in the clinic. A method based on the analysis of the impact produced by an instrumented hammer on the ancillary has been developed by our group (Michel et al., 2016a). However, the soft tissue thickness present around the acetabulum may affect the impact response, which may hamper the robustness of the method. The aim of this study is to evaluate the influence of the soft tissue thickness (STT) on the acetabular cup implant primary fixation evaluation using impact analyses. MethodsTo do so, different AC implants were inserted in five bovine bone samples. For each sample, different stability conditions were obtained by changing the cavity diameter. For each configuration, the AC implant was impacted 25 times with 10 and 30 mm of soft tissues positioned underneath the sample. The averaged indicator Im was determined based on the amplitude of the signal for each configuration and each STT and the pull-out force was measured. FindingsThe results show that the resonance frequency of the system increases when the value of the soft tissue thickness decreases. Moreover, an ANOVA analysis shows that there was no significant effect of the value of soft tissue thickness on the values of the indicator Im (F = 2.33; p-value = 0.13). InterpretationThis study shows that soft tissue thickness does not appear to alter the prediction of the acetabular cup implant primary fixation obtained using the impact analysis approach, opening the path towards future clinical trials.

Change impact analysis for evolving configuration decisions in product line use case models

Product Line Engineering is becoming a key practice in many software development environments where complex systems are developed for multiple customers with varying needs. In many business contexts, use cases are the main artifacts for communicating requirements among stakeholders. In such contexts, Product Line (PL) use cases capture variable and common requirements while use case-driven configuration generates Product Specific (PS) use cases for each new customer in a product family. In this paper, we propose, apply, and assess a change impact analysis approach for evolving configuration decisions in PL use case models. Our approach includes: (1) automated support to identify the impact of decision changes on prior and subsequent decisions in PL use case diagrams and (2) automated incremental regeneration of PS use case models from PL use case models and evolving configuration decisions. Our tool support is integrated with IBM Doors. Our approach has been evaluated in an industrial case study, which provides evidence that it is practical and beneficial to analyze the impact of decision changes and to incrementally regenerate PS use case models in industrial settings.

Developing and Assessing Alternative Land-Use Scenarios from the MOLAND Model: A Scenario-Based Impact Analysis Approach for the Evaluation of Rapid Rail Provisions and Urban Development in the Greater Dublin Region

In this study, environmental sustainability implications of planned rail infrastructure investments on the urban form and development in the Greater Dublin Region (GDR) have been analysed incorporating the scenario analysis approach. Various scenarios are developed using the MOLAND Model applications including: A baseline scenario incorporating a continuation of the present dispersed pattern of urban development and an alternative scenario with rail-oriented corridor development, under varying conditions of economic growth. An alternative scenario was also developed for the recessionary development case considering the prolonged recession in the GDR. Further explorations incorporating a Cost-Benefit Analysis (CBA) approach are developed to evaluate the sustainability implications of different land development scenarios in the Dublin Region. This is assisted by focussing on the impacts of rail investments on urban form and development as raised in the international comparative literature. The findings from the CBA assessment positively indicate that containment policies-as represented by the public transport oriented development indicate benefits over the dispersed development case by reducing the negative consequences of sprawl type of developments. In contrast, dispersed development in the baseline scenario indicates costs of continuation of such development patterns exceed the benefits in the long term. This study will contribute to policy support evaluation measures relating to the integration of scenario analysis tool with the CBA approach in assisting the evaluation of new transport infrastructure proposals.

Equivalent impact system approach for elastoplastic impact analysis of dissimilar spheres

The dynamic response during normal elastoplastic impact of dissimilar spheres, i.e. spheres of different sizes and material composition, is investigated theoretically. A new modelling approach, called equivalent impact system approach (EISA), is developed to perform detailed investigation on the local compliance response and rigid body motion of each sphere during normal elastoplastic impact of dissimilar spheres. The EISA is validated using results obtained from conventional modelling of two spheres. Also, the coefficient of restitution for impact of materially-dissimilar spheres was investigated using an effective yield strength formulation proposed in this study. The results show that the effective yield formulation predicts experiments better than the commonly used minimum yield formulation.

An Integrated WRF-CAMx Modeling Approach for Impact Analysis of Implementing the Emergency PM2.5 Control Measures during Red Alerts in Beijing in December 2015

ABSTRACTIn December 2015, the Beijing-Tianjin-Hebei (BTH) region experienced several episodes of heavy air pollution. Beijing municipal government therefore issued 2 red alerts on December 7 and 19, respectively, and also implemented emergency control measures to alleviate the negative effects of pollution. It is estimated that the heavy pollutions in 2 red alert periods in Beijing were due mainly to the accumulation of air pollutants from local emission sources and the transboundary transport of pollutants from surrounding areas. The collected meteorological and PM2.5 data indicate that the severity of air pollutions were enlarged by the poor meteorological conditions along with lower mixing layer height. In this study, the WRF-CAMx modeling system was utilized not only for analyzing the contributions of PM2.5 from different sources, but also for quantitatively assessing the effects of implementing various emergency control measures on PM2.5 pollution control during the red alert periods. The modeling results show that local emissions were the most dominant contributors (64.8%–83.5%) among all emission sources, while the main external contributions came from the city of Baoding (3.4%–9.3%). In addition, among 5 different emission source categories, coal and traffic were the two dominant contributors to PM2.5 concentration in urban area of Beijing. Then four pollution control scenarios were designed particularly to investigate the effectiveness of the emergency control measures, and the results show that, generally these emergency control measures have positive effects on air pollution reduction. In particular, restrictive measures of traffic volume control and industrial activity shutdown/suspension have been found as the most effective measures in comparison to other emergency control measures. It is recommended that such effective measures should be considered to implement when next time similar heavy air pollutions occur in the city of Beijing.

Toward automatically quantifying the impact of a change in systems

Software maintenance is becoming more challenging with the increased complexity of the software and the frequently applied changes. Performing impact analysis before the actual implementation of a change is a crucial task during system maintenance. While many tools and techniques are available to measure the impact of a change at the code level, only a few research work is done to measure the impact of a change at an earlier stage in the development process. Measuring the impact of a change at the model level speeds up the maintenance process allowing early discovery of critical components of the system before applying the actual change at the code level. In this paper, we present model-based impact analysis approach for state-based systems such as telecommunication or embedded systems. The proposed approach uses model dependencies to automatically measure the expected impact for a requested change instead of relying on the expertise of system maintainers, and it generates two impact sets representing the lower bound and the upper bound of the impact. Although it can be extended to other behavioral models, the presented approach mainly addresses extended finite-state machine (EFSM) models. An empirical study is conducted on six EFSM models to investigate the usefulness of the proposed approach. The results show that on average the size of the impact after a single modification (a change in a one EFSM transition) ranges between 14 and 38 % of the total size of the model. For a modification involving multiple transitions, the average size of the impact ranges between 30 and 64 % of the total size of the model. Additionally, we investigated the relationships (correlation) between the structure of the EFSM model, and the size of the impact sets. Upon preliminary analysis of the correlation, the concepts of model density and data density were defined, and it was found that they could be the major factors influencing the sizes of impact sets for models. As a result, these factors can be used to determine the types of models for which the proposed approach is the most appropriate.

A Static Change Impact Analysis Approach based on Metrics and Visualizations to Support the Evolution of Workflow Repositories

In ever-changing business environments, organizations continuously refine their processes to benefit from and meet the constraints of new technology, new business rules, and new market requirements. Workflow management systems (WFMSs) support organizations in evolving their processes by providing them with technological mechanisms to design, enact, and monitor workflows. However, workflows repositories often grow and start to encompass a variety of interdependent workflows. Without appropriate tool support, keeping track of such interdependencies and staying aware of the impact of a change in a workflow schema becomes hard. Workflow designers are often blindsided by changes that end up inducing side- and ripple-effects. This poses threats to the reliability of the workflows and ultimately hampers the evolvability of the workflow repository as a whole. In this paper, the authors introduce a change impact analysis approach based on metrics and visualizations to support the evolution of workflow repositories. They implemented the approach and later integrated it as a module in the HP Operations Orchestration (HP OO) WFMS. The authors conducted an exploratory study in which they thoroughly analyzed the workflow repositories of 8 HP OO customers. They characterized the customer repositories from a change impact perspective and compared them against each other. The authors were able to spot the workflows with high change impact among thousands of workflows in each repository. They also found that while the out-of-the-box repository included in HP OO had 10 workflows with high change impact, customer repositories included 11 (+10%) to 35 (+250%) workflows with this same characteristic. This result indicates the extent to which customers should put additional effort in evolving their repositories. The authors' approach contributes to the body of knowledge on static workflow evolution and complements existing dynamic workflow evolution approaches. Their techniques also aim to help organizations build more flexible and reliable workflow repositories.

Eroding societal trust: a game-changer for EU policies and institutions?

Trust is a fundamental condition for a fair and cooperative society. But what if trust collapses? This article is interested in the disrupting effects a further erosion or even collapse of trust could have for European Union (EU) policies and institutions. It is argued that a breakdown of trust could create serious risks, but also opportunities, and is therefore an important factor that the EU must consider when designing its future policies and strategies. To this end – by using a forward-looking and trend impact analysis approach – the article provides insights and options on how strategic political responses for the EU could look like to turn the trend around and again enhance trust in the European project. Empirically, it addresses issue and policy areas such as trust in political systems, justice, science, economic regulation, cyberspace, surveillance as well as ethnic and religious diversity.

A formal approach for change impact analysis of long term composed services using Probabilistic Cellular Automata

Incorporating changes into the logics of composed services dynamically and successfully is a challenge for sustaining a business’ image and profit in the society, especially when the change is expected to be made immediately at low cost. In this paper, we address this challenge by proposing a change impact analysis framework for long term composed services (LCS) which: (i) enables the business people to implement the changes by themselves through their analysts, (ii) reduces cost and time by eliminating the dependence on IT developers once the application services are developed and delivered, (iii) ensures effective incorporation of the changes made by using standard methodologies for evaluation – finite state automaton for verifying the runtime compatibilities and change evaluation and probabilistic cellular automaton for impact analysis and prediction. Through the evaluated probability measures and effective incident matching, the knowledge gained by the analyst over his service logics and the efficiency of incorporating changes are increased.

A forecasting model for drug utilization and expenditure integrating a Cellular Automata model with the Budget Impact Analysis approach. Preliminary results

Results The first-in-class emerging anti-diabetic dapagliflozin was selected and critically evaluated by the IHSP about 12 months before the European Marketing Authorization (MA). Other competitors already on the market were identified. A CA model describing the diffusion process of more than 200 Italian specialties of oral antidiabetic drugs (ATC A10B), sold between 2000 and 2014 has been developed and validated. A protocol for the identification of the real-world target population in the ARNO-CINECA database was set up on the grounds of the expected indication for dapaglifozin. The estimation of the budget impact of dapagliflozin is ongoing based on the estimation of market shares, through the application of the CA model, the analysis of the identified target population and the analysis of the potential variations in related healthcare costs for the treatment of type 2 diabetes, after the introduction of dapagliflozin.

A Change Impact Analysis Tool for Software Development Phase

Accepting too many software change requests could contribute to expense and delay in project delivery. On the other hand rejecting the changes may increase customer dissatisfaction. Software project management might use a reliable estimation on potential impacted artifacts to decide whether to accept or reject the changes. In software development phase, an assumption that all classes in the class artifact are completely developed is impractical compared to software maintenance phase. This is due to some classes in the class artifact are still under development or partially developed. This paper extends our previous works on developing an impact analysis approach for the software development phase in automating the approach which we call it CIAT (Change Impact Analysis Tool). The significant achievements of the tool are demonstrated through an extensive experimental validation using several case studies. The experimental analysis shows improvement in the accuracy over current impact analysis results.

Economic, organizational and budget impact of a new diagnostic plan for HCV detection: what’s “new”?

Hepatitis C (HCV) is a liver inflammation which, through the activation of the immune defense system, causes the death of liver cells (liver necrosis). Like Hepatitis B, it can become chronic, turning into a long term pathology. The aim of the present study was to evaluate a new technology useful to diagnose HCV, based on a serological kit HCVAg, comparing it with the standard technology, according to a multi-dimensional approach. In order to analyze the differences between the two technologies, three dimensions were considered: (i) process costs, (ii) organizational aspects and (iii) budget impact. Data were collected by observational analysis and supported with administrative data. Activity Based Costing methodology (ABC), and a Budget Impact Analysis approach (BIA) were implemented. The new technology reduced the time needed to complete a medical report to 90 minutes, with a positive organizational impact, and allowed an immediate definition of the presence or absence of HCV infection, with quantitative results. Data showed that its introduction would bring economic savings to the Regional and National Health Service: a hospital could reduce the direct and indirect costs by 47.90% each and contribute to a reduction in funding at Regional or National level by 26.96%. The introduction of the new technology, if compared with the standard one, would give similar effectiveness, with a lower organizational and economic impact, both for a hospital and for a Regional/National Health Service, with a good equity impact for HCV infected patients.

Impact of Socio-Demographics, Fuel Price and Airfare on the Domestic Overnight Travel Decision in Australia

Domestic overnight travel is one of the most significant sectors in the Australian tourism industry. Understanding the extent to which the crucial factors influence tourists' choice of overnight trip can be a key to successful marketing and strategic planning in the domestic travel industry. To understand the characteristics of the domestic overnight tourists, this paper analyses the data by means of a proposed new impact analysis approach, which overcomes some limitations of the conventional impact analysis approach. It also investigates how socio-demographic factors, fuel price and domestic airfares affect the probability of tourists opting for domestic overnight trips. Impact analysis is a method for analysing the association of the impact factor with the response variable in terms of estimated probability. This research demonstrates that household income, country of birth, life-cycle stage and home state are four of the most significant categories that generate the highest maximum impact on the overnight trip decision.

Change impact analysis for requirements: A metamodeling approach

ContextFollowing the evolution of the business needs, the requirements of software systems change continuously and new requirements emerge frequently. Requirements documents are often textual artifacts with structure not explicitly given. When a change in a requirements document is introduced, the requirements engineer may have to manually analyze all the requirements for a single change. This may result in neglecting the actual impact of a change. Consequently, the cost of implementing a change may become several times higher than expected. ObjectiveIn this paper, we aim at improving change impact analysis in requirements by using formal semantics of requirements relations and requirements change types. MethodIn our previous work we present a requirements metamodel with commonly used requirements relation types and their semantics formalized in first-order logic. In this paper the classification of requirements changes based on structure of a textual requirement is provided with formal semantics. The formalization of requirements relations and changes is used for propagating proposed changes and consistency checking of proposed changes in requirements models. The tool support for change impact analysis in requirements models is an extension of our Tool for Requirements Inferencing and Consistency Checking (TRIC). ResultsThe described approach for change impact analysis helps in the elimination of some false positive impacts in change propagation, and enables consistency checking of changes. ConclusionWe illustrate our approach in an example which shows that the formal semantics of requirements relations and change classification enables change alternatives to be proposed semi-automatically, the reduction of some false positive impacts and contradicting changes in requirements to be determined.

Considering Partially Developed Artifacts in Change Impact Analysis Implementation

It is important to manage the changes in the software to meet the evolving needs of the customer and hence, satisfy them. Accepting too many changes causes delay in the completion and it incurs additional cost. One type of information that helps to make the decision is the prediction of the number of classes affected by the changes or change impact analysis. Current impact analysis approaches assume that all classes in the class artifact are completely developed and the class artifact is used as a source of analysis since it represents the final user requirements. However, these assumptions are impractical for impact analysis in the software development phase as some classes in the class artifact are still under development or partially developed that leads to inaccuracy. This paper presents a novel impact analysis approach to be used in the software development phase. The significant achievements of the approach are demonstrated through an extensive experimental validation using several case studies. The experimental analysis shows improvement in the accuracy over current impact analysis results.

An Approach for Change Impact Analysis in Web systems - A Industrial Case study

There is a growing body of research on change impact analysis (CIA) approaches that specifically addresses changes and their impacts on architecture design. However, there is little research focus on approaches that particularly support the identification of impacts on architecture design resulting from business process changes i.e. early identification of change impacts in Web systems. To address this problem, we have proposed a systematic, structured and rigorous approach called as process model of CIA (PMCIA). PMCIA consists of a set of defined steps/activities, inputs, outputs, and employs architecture design information. In this paper we have presented the results of PMCIA validation in industrial setting through a detailed case study. The case study was carried out across two releases of a selected Web system project in an organization. The case study results indicate that the proposed approach, indeed, supports for early identification of change impacts in Web systems and provides Web developers the necessary components for systematically performing CIA.

An Impulse Based Substructuring approach for impact analysis and load case simulations

Abstract In the present paper we outline the basic theory of assembling substructures for which the dynamics are described as Impulse Response Functions. The assembly procedure computes the time response of a system by evaluating per substructure the convolution product between the Impulse Response Functions and the applied forces, including the interface forces that are computed to satisfy the interface compatibility. We call this approach the Impulse Based Substructuring method since it transposes to the time domain the Frequency Based Substructuring approach. In the Impulse Based Substructuring technique the Impulse Response Functions of the substructures can be gathered either from experimental tests using a hammer impact or from time-integration of numerical submodels. In this paper the implementation of the method is outlined for the case when the impulse responses of the substructures are computed numerically. A simple bar example is shown in order to illustrate the concept. The Impulse Based Substructuring allows fast evaluation of impact response of a structure when the impulse response of its components is known. It can thus be used to efficiently optimize designs of consumer products by including impact behavior at the early stage of the design, but also for performing substructured simulations of complex structures such as offshore wind turbines.

English

The land use practices around Lake Nakivale Wetland have over the last five decades changed from dominantly cattle keeping to crop farming, human settlement and urbanisation. This change, has increased food production and security, it has come at a cost to the natural environment in form of land degradation, wetland encroachment, loss of wildlife habitats and crucial wetland resources. Based on a research conducted in Lake Nakivale Wetland in Isingiro District in Uganda, this paper assessed the cost residents incur as wetland resources experience external disturbances from poor land use practices. Collection of data involved a household survey, interviews, focused group discussions and wetland resource ranking. The impact analysis approach was used to estimate the value of the affected wetland resources. This was based on the market price and the concept of willingness to either pay or accept compensation for wetland resources. The findings indicate that cost of poor land use practices on vital wetland resources is enormous, estimated to be worth US $ 2,943,960.3 per annum and is expected to continue to increase in the future, putting the livelihoods of residents in dilemma. Sustainable land use management based on sound land use planning and restoration program is proposed to minimise the negative effects of land use on the wetland. Key words: Land use practices, wetland resources, livelihoods, sustainable land use management, land use planning, wetland resource value.