A major concern for the case study researcher is the credibility of the case study from the preparation phase for evidence collection until the case study report is writing. Yin (2003) suggests the use of three types of validity tests and one reliability test to judge the quality of case study research. These include construct validity, internal validity, external validity, and reliability tests. Based on Yin’s (2003) recommendation, the use of a multiple-case study in data collection shows the appropriateness of this study’s construct validity. Internal validity in a case study research measures the confidence that can be placed on the cause and effect relationship in the study. The causal relationship between two variables should be properly demonstrated to ascertain that a particular inference has internal validity. This ensures that results of a study are not affected by unaccountable influences, but only by the particular phenomenon being studied. In this study, the phenomenon investigated is the extent to which conventional management accounting systems provide brewery process waste information to support and improve waste-reduction decisions in the South African brewery industry.
External validity refers to establishing the domain to which a study’s findings can be generalised (Seale 1999:40). That is, the extent to which causal propositions is
likely to hold true in other settings to warrant generalisation of findings. In this study, external validity is demonstrated through the use of a multiple-case study approach. Reliability assesses the reproducibility of results and conclusions. This may therefore imply the ability to obtain the same results from a different application. In a case study research, reliability requires that attention is given to both consistency and stability. It relates to the extent to which the research is authentic and true to life (Kumar 2008:51). It should be admitted that a new researcher investigating the same phenomenon to that of an earlier researcher will essentially be studying a different case since time and context would have changed. This may imply that different conclusions may be reached.
4.19. SUMMARY
The research methods used in this study has been explained in this chapter. A case study and an in-depth interview approach were adopted to address the research objectives. The in-depth interview method was used as the main data collection method. The open-ended questions employed in the interviews were used for data collection in order for the data analysis to be rich in description of the lived experience. The unit of analysis has been the brewery and individual participants from the two breweries. The study used research themes to summarise findings rather than reporting all the details. The next chapter presents the findings of the case study at the micro-brewery in South Africa.
CHAPTER FIVE
FINDINGS – THE CASE OF HOPE BREWERY
5.1 INTRODUCTION
This chapter addresses the first two objectives of this study by using a case study in Hope Brewery to understand the extent to which existing conventional MASs provide process waste information to support its waste-reduction decisions; and to assess the impact of the insufficiency of the process waste information provided through the conventional MASs on its brewery waste-reduction decisions. It is necessary to understand the current state of conventional management accounting systems used in the brewery industry to support process waste-reduction decisions, since extending and adjusting the use of MFCA to improve process waste-reduction decisions in the South African brewery industry is an unexplored area of research (see Table 4.1). In Hope Brewery, it was found that there are no established MASs to capture brewery waste-related cost information. Using a case study approach, this study demonstrates the relevance of MFCA to improve brewery waste-reduction decisions.
5.1.1 Goal of this chapter
The goal of this chapter is to discuss the findings, as well as lessons learned, in the micro-brewery during the conduct of the study. These include improvements made from the case study.
5.1.2 Layout of the chapter
This chapter presents the findings from interviews held with the participant of the micro-brewery, Hope Brewery which is provided in a visual representation in Figure 5.1. Section 5.2 presents a general background of Hope Brewery and an overview of its environmental obligations in relation to waste-reduction in the context of the National Environmental Management Act of 1998, South Africa (DEA 2010b). In Section 5.3, waste-management practices at Hope brewery are discussed. Then, the findings from the in-depth interview, as well as the pilot study, are addressed and discussed in Section 5.4. The extent of Hope Brewery’s current conventional MASs
to provide waste information to support waste-reduction decisions, and its perceived insufficiency, accounting for waste costs and management of waste information, are discussed in Section 5.4.1. An in-depth interview and the case study for Hope Brewery were conducted between 2011 and 2012 the data collected therefore are presented in Section 5.5. In Section 5.6, a summary of lessons learned from the in- depth interview and the case study was presented. The chapter concludes with a summary in Section 5.7.
The above layout is represented in Figure 5.1.
Figure 5.1: A visual representation of the layout of Chapter 5