ADMINISTRACIÓN Y CONTROL

The measurement tool was evaluated in terms of validity, reliability, practicability and generalisability.

3.13.1 Validity

Internal validity indicates the degree to which an instrument measures what it is supposed to measure (Saunders et al., 2012). It can also be defined as the extent to which the independent variable (supply chain responsiveness) causes the effects of the dependent variable (sustainable competitive advantage) (Glenn, 2010).

Validity in this study was reviewed in terms of content validity, criterion-related validity and construct validity. These are defined as follows:

 Content validity or the degree to which a measuring instrument provides coverage of the topic under study. Content validity in this study was achieved by using a measurement tool developed by using the results of the extended literature review (Chapter 2) to ensure that the main constructs discussed were covered in the survey questions. In this study, the measuring tool was used to assess: a) the

objectives of the study (how the different populations viewed supply chain responsiveness); b) the drivers that enabled supply chain responsiveness; and c) the link to sustainable competitive advantage for company GSC. The elements included in the measuring tool were based on sound theory and the judgement of the researcher to enable a close fit between the elements measured and the main constructs of the study.

 Criterion-related validity is the ability of the measures to make accurate predictions (Saunders et al., 2012:429). The study used a five-point Likert scale which was evaluated using a Cronbach’s alpha score to measure internal consistency. The scores for the different questions were evaluated against the information on the criterion used to predict the relationship between supply chain responsiveness and its drivers as prescribed by literature.

 Construct validity is the degree to which the measurement questions actually measure the presence of constructs that are intended to be measured (Saunders, et al., 2012:430). This study used multiple sources of evidence, namely, the extended literature review, internal perspective from employees, and external perception of customers to achieve construct validity (Yin, 2009:40).

A pilot study was conducted. The questionnaire was distributed to five employees in the sales department to determine if the questions were interpreted as intended. The responses were evaluated for any abnormalities and there were no changes required to the original questionnaire.

3.13.2 Reliability

A measuring tool is reliable if it produces consistent results. Reliability is concerned with the robustness of the questionnaire and whether it will produce consistent results at different times and under different conditions such as with a different sample (Saunders et al., 2012). The reliability of the questionnaire was assessed using Cronbach’s alpha which measures the consistency of responses to a set of questions that are combined as a scale to measure a particular concept. It consists of an alpha coefficient of between 0 and 1. Values of 0.7 or above indicates that the questions combined in the scale are measuring the same construct. Values of above 0.7 are acceptable for research purposes (Kurpius & Stafford, 2006).

The reliability of the research was increased as per the approach by Quinton and Smallbone (2006:130) by using the following three techniques:

 The use of different data sources. This was achieved by collecting information from the production facility, sales and marketing department and customers.

 The use of different data collection instruments. This was achieved by using two different questionnaires to assess customer perceptions and internal perspectives.

 The application of established theory. Theory and information from the body of knowledge was consulted and formed part of a robust literature review.

3.13.3 Practicability

Practicability of a measuring tool can be evaluated in terms of economy, convenience and interpretability (Kothari, 2004). The economy and convenience aspect was considered in terms of the budget and time available to conduct the research. The questionnaire was administered through the internet using the KwikSurvey platform which reduced the costs of administration and printing while providing a platform to collect data for statistical analysis. Printed surveys were distributed to respondents who preferred printed copies for convenience and were manually recorded on the SPSS 22 platform. The ‘interpretability’ of the questionnaire refers to the ability of the respondents to interpret the questions and the questionnaire as it was intended. That was achieved by issuing a covering letter that briefly explained the purpose of the study (Appendix A) and included a set of instructions per section as well as a brief overview on what the section intended to measure.

3.13.4 Generalisability

It was not the intention of the study to generalise the findings as the research was a cross- sectional specific case study of company GSC’s supply chain responsiveness. The objectives of the study were to understand the current supply chain responsiveness from the view of the customers and the employees and establish if supply chain responsiveness had a link to sustainable competitive advantage. The study was intended as a baseline that will guide further research.

3.14 Summary

In this chapter the research methods and approach are discussed in detail. In summary, a quantitative research approach is used for the study where quantitative primary data were collected using a self-administered questionnaire.

The next chapter focuses on discussing the findings from the questionnaires and establishes both the internal and external perspectives of the supply chain responsiveness of company GSC.