Research Framework

Triangulation of quantitative and qualitative methods was conducted in this study. As stated earlier, this study seeks to gain insight into determining factors for warehouse location selection in the humanitarian relief logistics, about which very little are known. This section briefly introduces the stages that the author took for the research. The detailed research method will be described in the next section.

The framework adopted in this study is essentially the sequential approach that was described by Mangan et al. (2004), who used both qualitative and quantitative methods are applied at different stages of the research. The findings of one stage are further refined to be used in the following stage. A similar framework is employed in this study. Silverman (2006) suggested that there could be three different ways of mixing quantitative and qualitative research. Firstly, using qualitative research to explore a particular topic in order to set up a quantitative study. For example, if you are designing a questionnaire on racial prejudice, it may be useful to begin by holding semi-structured interviews with community leaders and police officers together with focus groups composed of members of different ethnic communities. Secondly, beginning with a quantitative study in order to establish a simple of respondents and to

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establish the broad contours of the field. Qualitative research can then be used to look in depth at a key issue using some of the earlier sample. Thirdly, engaging in a qualitative study which uses quantitative data to locate the results in a broader context.

The research framework is summarised in Table 4.3. The first approach to combining methods as described above has been used in the current study. The qualitative method (i.e. a semi-structured interview with supply managers and officers) was employed in an exploratory stage in order to get a better understanding of the key issues of the determining factors for warehouse location selection in humanitarian relief logistics.

Table 4.3 Summary of the study framework

Stages Research Questions Methods Findings

Stage One - Humanitarian warehouse selection attributes (Q1)

- Literature Review - Exploratory Survey

- Identifying the major attributes for the warehouse selection

- Priorities among the attributes being studied Stage Two - Regional and specific site

determinant attributes in

humanitarian warehouse selection (Q2, Q4)

- Warehouse location sites for regional and specific site determinants (Q3, Q5)

- Two case studies with humanitarian relief organisations

- Identified the warehouse determinant for regional and specific site

- Identified the optimal warehouse candidate locations

- Hierarchical structure of the attributes being identified Stage

Three

- Priorities and weights of the attributes for warehouse location (Q2, Q4)

- Humanitarian warehouse optimal location (Q3, Q5)

- Descriptive survey research - Identifying the priorities among the factors

- Priorities of the attributes are identified

- Optimal warehouse location(s) is identified

Source: Author

The quantitative method (i.e. questionnaire survey) was used in this study to collect descriptive or explanatory data to seek the preferences of the factors used for the warehouse location selection and to evaluate the optimal warehouse sites. The combination of this method is expected to be an effective way to triangulate data collected by a questionnaire survey, which prevents delimiting the scope of the research by only using one research method. Further details about the research methodology are provided in relevant chapters.

Stage One:

 Literature Review: This sub-stage was the initial starting point of the study. An

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positioned warehouse was conducted. The use of key words when searching for literature helped to reduce time, as described by Bouma and Atkinson (1995). Keywords were very useful in narrowing the search efforts, namely: “pre-positioning”, “humanitarian”, “warehouse selection”, “MCDM”, “MADM”, “AHP”, and “TOPSIS”. Different sources were used during the literature review sub-stage, but mainly:

i. On-Line Journal Databases: These were primary sources of information mainly

because of these of search and their wide coverage of databases. The main databases used for literature review were: ABI Inform/Proquest, Emerald Library and EBSCO Business Source Premier. The search included academic journals, professional magazines and industrial reports.

ii. Cardiff University Library: The library provided access to a large stock of books, academic journals and professional publications.

iii. On-line Search: An internet search provided an overview of different issues, nevertheless unlike journal information; data available on the internet is less creditable.

Although the literature review was more general when it started, a more focused literature review was undertaken during this stage. In particular, high-level academic journals (such as International Journal of Production Economics, Expert Systems with

Applications, and International Journal of Physical Distribution and Logistics Management) were reviewed. The main goal of this specific literature review was to

identify the determining factors used for warehouse selection which have been cited to date (especially in humanitarian relief logistics) and to find suitable research methods. The literature review resulted in identifying the suitable multi-criteria decision making research method for analysing the optimal site selection, which was conducted to further examine the strengths and weaknesses of the various research methods.

 Exploratory Survey: The determining factors for selection of the warehouse locations

and the priorities of those factors have been used as the basis for the next research step of Case Study A and B. The author established contacts with supply chain managers and officers in a humanitarian organisation that operates pre-positioning warehouse strategy. The author conducted face-to-face and telephone interviews. Electronic mail and video calls were made to confirm the factors that were that were identified and the

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respondents were asked to give their opinions on the priorities of their warehouse strategy. Additionally, data obtained from the survey were refined and used for the case study survey conducted later in the research process. Further details about the exploratory survey are mentioned in the next section and its results can be found in Chapter 5.

Stage Two:

In order to gain further insights into international humanitarian organisations‟ pre- positioning warehouse strategy, the author undertook two case studies of the optimal warehouse selection with its own determining factors. The author conducted the cases during a two month internship in International Humanitarian Organisation A and other humanitarian organisations that are based in Dubai.

 Case Study A: The researcher undertook a case study of an international

humanitarian organisation in order to gain more insight into regional (i.e. macro) determinant warehouse positioning strategy. This is an organisation that mainly operates with refugee related relief matters but which also becomes involved with providing relief of natural disasters. The humanitarian warehouse determining factors were studied with the managerial level decision-makers in the headquarters and in the field. The author participated in the weekly meetings and daily operational meetings in the organisation as an intern. The interviews were conducted with the senior and junior officers in order to verify the factors and to prioritise the factors that are used for their organisation. In addition, the study of optimal location for warehouse selection was conducted to see whether their decisions of locating the current warehouse locations were suitable.

 Case Study B: The second case study was conducted to seek the specific site

determining attributes that were used in the humanitarian organisations based in Dubai, UAE. The author participated in a project where the international organisations were seeking to relocate the warehouse location for their operation. The alternative locations were identified with the determining factors that were used to access the locations.

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Stage Three:

In this stage, the researcher employed a descriptive survey based on the outputs of the second stage in order to determine the extent of the weights/prioritisation, preferences, and to solve the location selection problem for the optimal site selection. Regional determinant attributes were evaluated for Case Study A and specific site attributes for humanitarian organisations based on Dubai, UAE were identified and analysed. A group decision-making technique of the decision-making level managers are adapted to identify the alternative warehouse location and to determine the hierarchical structure of the factors that were identified in second stage of the research. Combinations of AHP and TOPSIS was employed to analyse the survey data; these are both qualitative and quantitative analysis methods. Fuzzy set theory is adapted to ensure more robust results for the warehouse selection. Fuzzy set theory is used in many decision making problems because it deals with vagueness of human thought (Zadeh, 1965). Sensitivity analysis were carried out for getting accurate results. The idea of sensitivity analysis is to exchange each criterion‟s weight with another criterion‟s weight (Önut et al. 2010). The detailed calculations of the use of AHP, TOPSIS, and fuzzy set theory are explained in next sections.

4.3.1 Semi-Structured Interview

This section is divided into two categories: the first category is the justification for choosing a semi-structured interview and the second describes the sampling and administration of the interview.