Figure 2
The flowchart shows a vertically aligned structure. At the top, a rectangular box is given and labeled “R Q 1. From a logistics management viewpoint, what are the key criteria for adopting drones in L M D?”, “R Q 2. What are the potentials, challenges and solutions associated with each criterion for adopting drones in L M D?”, “R Q 3. What relationships can be identified among the criteria for adopting drones in L M D?”, and “R Q 4. What further research directions for the logistics management field can be identified for adopting drones in L M D?”. The flow begins from the top dashed rectangle labeled “Pre-S L R steps”. Inside this dashed rectangle, the first text box is labeled “Reviewing traditional L M D literature”. From “Reviewing traditional L M D literature”, a downward arrow arises and points to a text box labeled “Identifying 12 L M D criteria for drone assessment”, also in the “Pre-S L R steps”. From “Identifying 12 L M D criteria for drone assessment”, a downward arrow arises and points to a text box labeled “Analytical framework (Figure 1)”, which is also within the “Pre-S L R steps”. From “Reviewing traditional L M D literature”, a right-pointing arrow arises and has a text box on it labeled “R Q 1”, which points to a text box labeled “Section 2”. From “Analytical framework (Figure 1)”, a downward arrow arises and points to a text box labeled “Inspecting scoping studies on drones”. From “Inspecting scoping studies on drones”, a downward arrow arises and points to a text box labeled “Identifying keywords”. From “Identifying keywords”, a downward arrow arises and points to a text box labeled “Applying keyword combinations (Table 3)”. From the dashed rectangle at the top labeled “Pre-S L R steps”, an arrow arises and points toward the “Identifying keywords” box. From “Applying keyword combinations (Table 3)”, an arrow arises and branches downward into two parallel boxes placed side by side. The left box is labeled “534 articles (Scopus)”, and the right box reads “591 articles (WoS)”. Both of these boxes have arrows that merge and extend downward, pointing to a text box labeled “Eliminating duplicate or unavailable content”. On the right side of the two arrows arising from “Applying keyword combinations (Table 3)”, there is a box titled “Initial inclusion criteria”. It contains four bullet points as follows: “Peer-reviewed journals”, “English”, “In Scopus or W o S”, and “Covers drones in L M D”. From this box, a leftward-pointing arrow arises and points to the arrow arising from “Applying keyword combinations (Table 3)”. From “Eliminating duplicate or unavailable content”, a downward arrow arises and points to a text box labeled “499 articles for advanced review”. From “499 articles for advanced review”, a downward arrow arises and points to a text box labeled “286 articles passed”. On the right side of the arrow arising from “499 articles for advanced review”, a box titled “Advanced inclusion criteria” is placed. It lists two bullet points as follows: “Set 1: Relevant title plus keyword plus abstract”, and “Set 2: Relevant abstract plus content”. From this box, a leftward-pointing arrow arises and points to the downward arrow arising from “499 articles for advanced review”. From the dashed rectangle at the top labeled “Pre-S L R steps”, another arrow arises and points toward the “Advanced inclusion criteria”. From “286 articles passed”, a downward arrow arises and points to a text box labeled “21 articles added (snowballing)”. From “21 articles added (snowballing)”, a downward arrow arises and points to a text box labeled “307 articles for final analysis”. From “307 articles for final analysis”, a downward arrow arises and points to a text box titled “Coding articles”. It contains two bullet points as follows: “Descriptive analysis”, and “Deductive coding from Figure 1 of L M D criteria”. Below “Deductive coding from Figure 1 of L M D criteria”, two more sub-points are given: “Potentials, challenges and solutions of drones in 12 L M D criteria”, and “Relationships between 12 L M D criteria”. From the dashed rectangle at the top labeled “Pre-S L R steps”, another arrow arises and points toward the “Coding articles”. From “Coding articles”, a downward arrow arises and points to a dashed rectangular box at the bottom titled “Creating narratives”. Inside this box, four text boxes are shown arranged vertically and labeled from top to bottom as follows: “Descriptive analysis”, “Thematic analysis (12 L M D criteria)”, “Cross-thematic analysis (relations between 12 L M D criteria)”, and “Further research directions”. On the right of this dashed rectangle, another dashed rectangle is shown titled “Reporting results”. Under “Reporting results”, four text boxes are arranged vertically and labeled from top to bottom as follows: “Section 4”, “Section 5”, “Section 6”, and “Section 7”. From “Descriptive analysis”, a right-pointing arrow arises and points to “Section 4”. From “Thematic analysis (12 L M D criteria)”, a right-pointing arrow arises and has a text box on it labeled “R Q 2”, and points to “Section 5”. From “Cross-thematic analysis (relations between 12 L M D criteria)”, a right-pointing arrow arises and has a text box on it labeled “R Q 3”, and points to “Section 6”. From “Further research directions”, a right-pointing arrow arises and has a text box on it labeled “R Q 4”, and points to “Section 7”. The caption below the flowchart reads “Adopted SLR steps