# A Taxonomy of Technologies for Human-Centred Logistics 4.0
## 2 Methodology  
The research methodology adopted to devise a proper taxonomy of technologies to guide practitioners in choosing the most suitable technological applications in industrial contexts is composed of several steps, that will be described in the following. According to the Oxford Dictionary, a taxonomy represents \"the scientific process of classifying things\" or \"a particular system of classifying things\". Since the main objective of taxonomies is to classify something, they represent a qualitative research design method, able to adapt to novel and scantly explored topics since they bring order in complex domains, and can be used for ex post theory building [10]. In particular, concerning technologies, taxonomies offer definitions and distinctions, and help define specifications for implementation [11]. Although taxonomies are often developed ad hoc for specific topics, it is also possible to find in literature structured approaches to build them, including both inductive and deductive approaches [10; 12]. Generally, developing a taxonomy is a multistep process that involves identifying a classification scheme, and evaluating the population according to the proposed scheme [13]. To meet the purpose of identify a classification scheme, designing a taxonomy includes (i) defining the units of classifications (i.e., categories); (ii) describing the different attributes (i.e., dimensions) of each category; (iii) assigning the subject instances (i.e., objects) to the defined categories and dimensions. Following this scheme, in this paper, we develop a taxonomy based on a deductive approach; in Figure 1, the research workflow is presented, adapted from the conceptual-to-empirical process proposed in [10; 14]. The research starts from the definition of the three categories for the taxonomy; one--the internal logistics activities--has been derived directly from literature, while the other two--the flow types and the human-technology relation--have been conceptualized ex novo by the authors, based on both scientific literature and on the authors previous experience concerning these topics. At this point, a review of the extant literature concerning internal logistics activities, flow types and the human-technology relation has been performed (Step 1). Relevant literature has been retrieved from well-established databases such as Scopus, Web of Science, Google Scholar, and ScienceDirect to be inclusive concerning the publications types (e.g., journal papers, conference proceedings). This literature analysis, presented in Section 3.1, has two objectives: first, to identify and conceptualize the categories that will be used for the classification, specifying the different dimensions for each of them (Step 2.1); second, to identify the population of taxonomy objects to be classified (Step 2.2). The categories are generally chosen following the purpose of the study, and this choice is recognized as a crucial step in taxonomy development [10]. A deductive line of reasoning has been followed in this study to understand the domain of interest and propose the categories [15]. For each category, then, the dimensions of classification have been defined (Figure 2). The explanation of all the categories and their dimensions is presented in Section 3.1. The following research step (Step 3) has been the examination of all the objects of the population (i.e., the technologies) according to the defined categories. In doing this, each technology has been analyzed according to the definitions and the application examples found in the literature (see also Table 5 in Section 3.2). Figure 1: Research workflow. At this point, the first draft of the taxonomy has been created (Step 4). After this first attempt in the classification of technologies, it appeared clearly that a minor revision of the category related to the logistics area was required. In particular, some areas have been merged into a unique dimension since there was complete overlap between them as stated in the introduction of Section 4.