Lucienne Blessing Université du Luxembourg Autumn Lecture-Workshop series University of Bath, 19 November 2009 Developing a Reference Model: the line of argumentation behind your research

University of Bath, 2009Lucienne Blessing2 Reference and Impact model Reference Model: Aim: to clarify and illustrate the main line of argumentation, that shows the relevance of your research topic and of the factors, that are most suitable to address in order to solve the problem. represents the current, identified or assumed situation in design Impact Model Aim: to clarify and illustrate the main line of argumentation, that shows of your line of attack and the expected effects. represents the expected, improved situation in design, resulting from the solution to be developed in the research project

University of Bath, 2009Lucienne Blessing3 Example project Goal: Improve the reliability of products to improve product performance (increase sales) Hypothesis: Timely assessment of reliability increases the chances of improving product reliability and improve product performance Research question: Is that true, and how to do that?

University of Bath, 2009Lucienne Blessing4 Setting up the Initial Reference Model Determine the initial set of influencing factors thought to be relevant those factors that may be suitable success criteria; the believed links between the factors in the existing as well as the desired situation, in particular those linked to the success criteria; Add any related assumptions Represent every statement with two (or more) nodes and links Make explicit current understanding and beliefs

University of Bath, 2009Lucienne Blessing5 Setting up the Initial Reference Model Start building a network, by linking statements, beliefs. Improve the reliability of products to improve product performance (increase sales) Product reliability Maintenance cost Amount of profit Market share + + _ _ _ [A] _ Company image _ _ [A]

University of Bath, 2009Lucienne Blessing6 Adding sources Source Edges are labelled with the source of the statement [x] = publication number. [A] = assumption, [E] = experience, [O] = own study. Contradicting or differing sources are represented using separate edges Edges can be given a width representing the strength of the relationship Product reliability 00 + _ Use of DfR-methods [E] [A] Product reliability 00 + _ [E] [A] Check any link to see the extent to which these have been shown to exist, or can be expected to exist using the evidence available.

University of Bath, 2009Lucienne Blessing7 Contradicting sources and additional factors Product reliability Customer satisfaction Market share [1] Price _ _ + 0 [2] Other factors [A] [1] + _ Quality of product Quality of production _ _ [1] Note: Relationships cannot simply be reversed: if high costs lead to reduced sales, this does not imply that low costs lead high sales. Factors known or expected to influence the network, but outside the scope of the research project, are added but with dashed lines, Contradicting findings are represented by multiple links between two nodes

University of Bath, 2009Lucienne Blessing8 Combinations of factors When two factors, having a particular value, together effect another factor (a statement involving three or more factors) a connecting line between the two edges is added near the affected factor and with a single value near the connecting line. Product reliability 0 + Use of DfR-methods % of project time left to improve _ Product- specificity of the method 0 _ + [E] [A]

University of Bath, 2009Lucienne Blessing9 (iterations between Research Clarification and Descriptive Study I stage) This is likely to reveal a network of links based on intermediate influencing factors, e.g. product reliability is linked to product performance, which is one of the factors influencing market share Supporting statements (links) related to other influencing factors might be available in literature Evidence from literature might be incomplete but it can be expected (assumption) that certain factors can be linked Refining the Reference Model Use literature to add relevant links

University of Bath, 2009Lucienne Blessing10 Criteria Criteria: desired values of the factor the research project sets out to understand and/or influence as described in the research goal. A project can have several criteria A criterion can be relative or absolute, qualitative or quantitative Criteria are needed to be able to judge the outcome of the research against the goals, i.e. whether the goals have been achieved Criteria about the research process are needed, but not considered in the Reference and Impact Models Measurable criteria, Criteria linked to the chosen success criteria that can be applied to judge the outcomes of the research given the resources available within the project or programme. The term measurable refers to the possibility of measuring the criteria during the project not to particular types of method. Success criteria Relate to the ultimate goal to which the research project or programme intends to contribute. These criteria usually reveal the purpose of the research and the eventual, expected contribution to practice. Select criteria

University of Bath, 2009Lucienne Blessing11 Use of DfR-methods Success Criterion Product reliability Customer satisfaction Market share [1] Price _ _ + 0 [2] Other factors [A] [1] + _ Quality of product Quality of production _ _ [1] Maintenance cost _ + + Warranty cost [4] [3,4] [3] + Operating cost + + _ [3] [5] Measurable Criterion 0 + % of project time left to improve _ Product- specificity of DfR- methods 0 _ + [E] [A] Key Factor Reference Model

University of Bath, 2009Lucienne Blessing12 Initial Impact Model (partial model) % of project time elapsed until detection Product reliability Amount of time needed for development _ [A] + Assessing reliability in early design stages _ _ _ [A] Other factors Support

University of Bath, 2009Lucienne Blessing13 Factors Influencing factor (node) Aspect of the existing (or desired/expected) situation considered relevant represented as a node Formulated as attribute + element Example: quality of (attribute) problem definition (element). Wrong: Problem definition (no attribute) introduces ambiguity: time spent on problem definition?, quality of the problem definition? or knowledge about the source of the problem definition,? etc. The attribute determines the link to other factors. Operational definition possible, i.e. should be possible to be assessed. Key factor influencing factor to be addressed by the proposed support. Example: quality of problem definition Quality of problem definition Attribute Element

University of Bath, 2009Lucienne Blessing14 Statements Link Represents the link between factors. ( = directed (causal) link) quality of product definition level of customer satisfaction Statement Attribute Element Link (causal) Factor

University of Bath, 2009Lucienne Blessing15 Statements Existing (or desired/expected) value of an attribute Attached to the links near the factors by means of +,, or 0. Example: -near factor quality of product indicates poor quality. Ensure that attribute values are unambiguous by precise labelling of the nodes: leadtime is + might mean leadtime is positive (i.e. short) or leadtime is long(er). Amount of leadtime is less unambiguous. quality of product level of customer satisfaction + + Statement Value of attribute Link (causal) Source [1]

University of Bath, 2009Lucienne Blessing16 Determining the need for a detailed Descriptive Study Based on the gained understanding determine whether sufficient evidence is available to identify the line of attack or whether a detailed Descriptive Study is necessary to determine missing links or to verify assumptions. If a detailed Descriptive Study is necessary: Refine the research problem into research questions or hypotheses to be addressed in the project. If sufficient evidence is available Identify the line of attack, i.e. the factors to be addressed in order to improve the identified situation and to achieve the aim. Start a Prescriptive Study by setting up the Impact Model, to illustrate the improved situation.

University of Bath, 2009Lucienne Blessing17 Task Develop an initial reference model for your research project Use a large sheet of paper to present your model If time allows and if relevant for your project, develop an initial impact model Good luck and have fun!