Mahmut Sonmez

Purchasing professional services: which decision criteria?

Purpose – The aim of this paper is to report the findings of a global survey on decision criteria used and the importance attached to these criteria when purchasing professional services for skills training in sales and negotiations.Design/methodology/approach – The research is based on 24 face‐to‐face and telephone interviews with global learning and development managers plus 309 usable responses to an online survey. The respondents are asked to evaluate the importance of six “high level” criteria and 37 sub‐criteria (identified from the interviews and academic literature review) when purchasing professional services. Descriptive statistics and exploratory factor analysis are used to analyse the survey data.Findings – Descriptive statistics reveal that the main criteria split into two distinct groups: pre‐qualifiers and final stage differentiators. Exploratory factor analysis results in a reduced set of 11 factors that explain the underlying structure of decision criteria used for the selection of profes...

Data transformation in the evidential reasoning-based decision making process

This paper describes the application of an evidential reasoning (ER)-based decision making process to multiple-criteria decision making (MCDM) problems having both quantitative and qualitative criteria. The ER approach is based on the decision theory and the theory of evidence and it uses the concept of ‘degree of belief’ to assess decision alternatives on each attribute. When faced with MCDM problems, evaluation and selection or ranking of alternatives appear to be both challenging and vital to arrive at a rational and robust decision. In the presence of both qualitative and quantitative evaluations in an MCDM problem, it is necessary, when using the ER-based decision making process, to transform or convert quantitative data into a belief structure using a number of grades so that the converted belief structure and the original quantitative data are equivalent in values or utilities. This paper suggests three scenarios for data transformation and examines how the ranking of decision alternatives is changed when different scenarios of data transformation are used. Ranking of UK universities using the ER approach is illustrated as an example.