The verification of a study is an important criterion of quality regarding:
• Representative nature of questioned target groups for the segment (Nonresponse bias)
• The model’s completeness and quality of participants (see introduction)
• The quality of the questionnaire after testing answers for consistency and plausibility
• The normal distribution of total maturity as proof of the model’s non polarity
• The basic assumption of the total success of the application of portfolio management
Target group reached – the segment is representative and the contact persons are responsible deciders of global product development
A target group’s verification to ensure its representative nature occurs with regard to possible distortions (Nonresponse bias). Levied variables of company demographics (employee count and revenue) are compared to those of not participating companies from the same segment (Banker et al. 2006). This serves as an estimation of a participant’s representative nature by means of a demographic comparison with a larger group of companies, allowing the use of the results for the larger group. There were no statistically significant differences between participating and nonparticipating companies in the individual segments. Companies from the region Germany, Austria and Switzerland, whose KPIs are available in public databases, were taken into consideration.
Another crucial criteria of good empirical studies are not only the investigated model’s completeness, but also the identification of the relevant participant target group. The disciplines describing the model in this case can be seen as complete, which, as affirmed by the participants, are free of overlap and have significantly different characteristics. The quality of questions posed was guaranteed by testing consistency in answering behavior for single disciplines as well as interdisciplinary. Maturity values ascertained by the study are plausibly distributed and move within a confidence interval of 95 percent. The results also exhibit normal distribution.
Basic assumption confirmed – degree of maturity and statements concerning success of portfolio management clearly correlate
The motivation behind measuring maturity in portfolio management with the goal of increasing it step-by-step and in a targeted manner was supported by the thesis that correct and timely application of portfolio management absolutely positively influences success in product development and the satisfaction of the company’s responsible employees. Regression analysis provides the essential proof of the internal connection between maturity levels and the participant’s declared portfolio success. The linear correlation between the perception of success and personal satisfaction, and the company’s achieved total maturity is clear to be seen. The regression’s significance is supported by the degree of dispersion of the answers, as well as a clear bordering of the prediction interval for a 95 percent prediction of the location of another trait.