Basis For Decision Support Research Articles

The Performance of Construction Firms: A System Approach

Traditionally, construction firms assessed their performance solely in financial terms. However, changing stakeholders’ and shareholders’ requirements have put pressure on them to evaluate their performance more broadly, and also to understand the behavior of the business environment better. This has led to the need for a holistic identification of main factors or ‘forces’ which influence the performance of construction firms. A system model is used to present a holistic view of the construction environment showing the possi-ble interactions between these forces. System theory is proposed as being a means of modeling the complex interactions between the factors in order to provide the basis for a decision support system. Data was col-lected from a number of sources including industry, literature and academics. Difficulties encountered in obtaining this because of its complex nature are discussed and the solution adopted described. This data is used as the basis for a soft system model of the whole company and its interactions. The developed hard sys-tem models of specific areas are described. It is concluded that systems theory offers an opportunity to pro-duce realistic models which can form the basis for decision support in construction companies. Keywords: system thinking, construction environment, company performance

Decision support tools for urban water and wastewater systems – focussing on hazardous flows assessment

The Swedish research programme Urban Water has developed a concept of a multi-criteria basis intended to support decision-making for urban water and wastewater systems. Five criteria groups were established for sustainability assessment of urban water systems: Health and Hygiene, Environment, Economy, Socio-culture, and Technology. Each criterion requires a set of indicators corresponding to quantifiable facts and figures, or qualitative data to comparatively assess the different alternatives in the decision process. The decision support process starts as a baseline study where the existing conditions are addressed. Alternative strategies of the future urban water system are developed and analysed by different tools and methodologies in assessing the five criteria groups. Eventually, the results and conclusions are integrated and synthesised into a basis for decision-making. As an example of a decision support basis for chemical safety, a barrier perspective was introduced to find out if and to what extent hazardous substances can be stopped, diverged, or transformed at various points in the wastewater system. A set of barriers was suggested, i.e. behaviour, systems design, process design, optional recipients, and organisational. The barrier approach was applied to two alternative municipal wastewater system designs--a combined wastewater system vs. a source separated system--analysing the fate of phosphorus, cadmium, and triclosan. The study showed that the combined system caused a higher substance flow to the receiving waterbody than the separated system. The combined system also brought more phosphorus and cadmium to the farmland than the separated system, but only half the amount of triclosan.

Development of diagnostic reference frames for seizures. Part 1: inter-participant agreement in the selection of symptoms

Objective: Our aim is to develop reliable descriptions of various seizure types, which will be used as a basis for decision support. We use expert opinions in this process. In this contribution we evaluate the inter-participant agreement in the selection of frequently occurring symptoms for the description of seizure types. Method: We compared the actual agreement among participants with the agreement that would result from random symptom selection as well as with the maximal agreement attainable. For each seizure type we calculated the reliability coefficients of the responses. Results: For all seizure types we found that the agreement in symptom selection among the participants is significantly higher than expected by chance, but not reaching the maximum agreement attainable. The reliability coefficients varied between 0.56 and 0.74 for the various seizure types. Conclusion: Although the participants do not reach the maximum agreement attainable in the selection of symptoms, the majority agreement on characteristic frequently occurring symptoms for the different seizure types does approach the maximum agreement attainable. Therefore, we conclude that expert opinions can be used for building descriptions of seizure types. However, to derive a reliable set of symptoms for the construction of the diagnostic reference frames (DRFs) more participants are needed.

Philosophy of science, policy sciences and the basis of decision support with LCA Based on the toxicity controversy in Sweden and the Netherlands

Current LCA implicitly assumes that a single rational truth can be found. Mainstream policy sciences has taken a different starting point when analysing decision making in complex and controversial societal debates for already several decades. In such debates, in general, more than one reasonable conceptualisation or ‘framing’ of the problem is at stake which forms the core of the controversy. This paper analyses the Dutch chlorine debate and the Swedish PVC debate and shows that (three) frames also play a role in toxicity controversies: the risk assessment frame, the strict control frame, and the precautionary frame. The latter frame, adhered to by the environmentalists, seeks to judge substances mainly on their inherent safety. The cases show that this logic may be defended as at least being equally reasonable to the emission-effect calculations that form the core of Risk Assessment and Life-cycle Impact Assessment (LCIA). As predicted by policy sciences, this finding implies that the political neutrality of tools like LCIA is questionable. In summary, the approaches and procedures developed for LCA have to be reconciled with key lessons from policy science and philosophy of science, i.e. considering the fact that multiple realities play a key role in many decision making processes. This paper suggests some alternative indicators for toxicity evaluations, and indicates the implications of LCA method development.

Raw milk grading using fuzzy logic

In this paper the current raw milk standard specification for Zimbabwe is reviewed. The hygienic quality and the compositional quality parts of the standard are recast in fuzzy logic terms and linked with rule bases to form a structured judgment system for grading both the hygienic and compositional quality. These may also be merged to provide an overall or total quality assessment. The structured judgment system is applied to two raw milk samples from different sources. The data from the one sample yield a higher hygienic quality rating than the data from the other, but a lower compositional quality rating. A total quality rating is found for each of the two samples and compared. The structured judgment system provides a clearer and more comprehensive assessment than the currently used system, and since it embodies an expert system element there is also a conclusive opinion of the grading in the form of membership values of certain sets. It therefore goes farther than the present system as the basis for decision support.

Competence Requirements and Their Impact on Manufacturing System Performance

Research into “Next generation manufacturing systems” stresses the use of semi-automated systems to handle short product life cycles and customer oriented production. Despite increasing dependency on technology, the importance of humans is expected to increase and to provide a realistic basis for decision support, both technical and organisational processes must be included in simulation models. In a rapidly changing environment, skill development is also important and should be considered when developing simulation models. This paper describes two case studies where competence and skill development were modelled using learning curves to obtain a more representative simulation of system performance.

Nitrogen effects in sugar beet growing: a module for decision support

PIEteR, a field-specific production model for sugarbeet in the Netherlands, is described. The model was developed as a basis for decision support, for example in determining N fertilizer requirements. Root and sugar yields, sugar content, (K + Na) and alpha -amino-N contents, extractability index, operating receipts (a measure for financial returns) and residual nitrogen in leaves are modelled as function of N availability, defined as (N-fertilizer rate + Nmin, 0-60 cm (soil, February)), and included in PIEteR as a so-called 'N-module'. Analysis of experimental data showed that root and sugar yield were optimal at 240 and 200 kg N ha-1, respectively. Sugar content and extractability index decreased, and (K + Na) and alpha -amino-N contents and fresh leaf yield increased with increasing N-availability. The operating receipts were optimal with 180 kg ha-1, or with a nitrogen fertilizer rate of 130 kg ha-1, assuming an Nmin-amount in soil in February of 50 kg ha-1. The results of the analysis were the basis for the functions in the N-module. In an independent test on data of 100 fields, the prediction errors for root and sugar yields and financial results decreased by about 2% and the explained variances increased by about 15% by including the N-module.

An analytic basis for decision support in negotiations

Mediators increase the effectiveness of negotiation processes. The art of mediation includes interpersonal skills, ability to convince, and proficiency in argumentation. The science of mediation represents an analytical approach to problem solving, a systematic analysis of the process, of players' positions, and of their goals, aspirations, and concessions. Analytical tools for mediation can be used by mediators, but these tools can also support negotiators in their analysis, verification of their positions, and choices. The knowledge of effective and safe alternatives, of sets of compromises, and the knowledge of the possible outcomes of concessions may be used to develop an effective strategy and to increase a negotiator's bargaining power. Models to analyze alternatives, to verify concessions made by the opponents, to determine effective alternatives, and to search for solutions that yield mutual gains, to aggregate opponents' proposals, to look for coalition members, and to simulate some of the actions of a mediator are discussed in the article.

A Hybrid Approach to Information and Decision Support Systems: Hazardous Substances and Industrial Risk Management

This paper describes a large-scale, model-based decision support system with embedded Artificial Intelligence (AI) technology, and a largely symbolic color graphics user interface. Designed for industrial risk assessment and the management of hazardous substances, its primary purpose is to allow the efficient use of methods of analysis and information management and to provide a powerful tool in the hands of planners, managers, policy and decision makers. This new generation of model-based decision support system should lead to a more informed, structured, comprehensive and interdisciplinary management of hazardous substancesTo facilitate access for the non-technical user, and for more experimental and explorative use, it proved necessary to build much of the accumulated knowledge on the subject areas into the user interface. Thus, the interface incorporates elements of knowledge-based expert systems that are capable of assisting any non-expert user to select, set up, run, and interpret complex technical software. By providing a coherent, integrated user interface, the interactions between different models, their data bases, and software for display and analysis become transparent and the substantive information basis for decision support can be considerably enlargedAs a central component of this hybrid decision support tool, a heterarchical, object-oriented information system on hazardous substances has been incorporated. It provides aggregated as well as detailed information for non-specialist users and allows easy modular updating with automatic consistency checking. To cover all the different viewpoints under which one can group hazardous substances (e.g., chemical compounds, toxicity, etc.) an object-oriented heterarchy of viewpoints, groups, and subgroups, down to the elementary substances, has been set up. Each object is activated when accessed, provides its descriptive data, refers to and derives data from other objects. In addition, every object statically inherits all the descriptive data and activities from all its predecessors in the heterarchy