Table 3.
Hot, cold, and steady topics/methods
| Topics | Trendline | Slope (x-value) |
|---|---|---|
| Hot topics (research themes) | ||
| Patients waiting time and COVID-19 | Upward | Positive |
| Industry 4.0 technologies | Upward | Positive |
| Sustainable operations and supply chain | Upward | Positive |
| Circular economy | Upward | Positive |
| Service-ecosystem | Upward | Positive |
| Knowledge management | Upward | Positive |
| Behavioural OSCM | Upward | Positive |
| Risk and resilience | Upward | Positive |
| Humanitarian logistics | Upward | Positive |
| Pharmaceutical supply chain | Upward | Positive |
| Climate change | Upward | Positive |
| Healthcare logistics | Upward | Positive |
| Literature reviews | Upward | Positive |
| Cold topics (research themes) | ||
| Outsourcing | Downward | Negative |
| Business process reengineering | Downward | Negative |
| Marketing | Downward | Negative |
| Warehousing | Downward | Negative |
| Operations strategy | Downward | Negative |
| Hot topics (research methods) | ||
| Markov method | Upward | Positive |
| Mixed-integer programming | Upward | Positive |
| Simulation | Upward | Positive |
| Stochastic programming | Upward | Positive |
| Queueing model | Upward | Positive |
| Mathematical programming | Upward | Positive |
| Structural equation modelling | Upward | Positive |
| Empirical research | Upward | Positive |
| Longitudinal study | Upward | Positive |
| Action research | Upward | Positive |
| Mixed-method studies | Upward | Positive |
| Steady topics (Steady methods) | ||
| Goal programming | Steady | Positive |
| Multilevel analysis | Steady | Positive |
| Cold topics (research methods) | ||
| Heuristic | Downward | Negative |
| Game theory model | Downward | Negative |
| Hierarchical linear programming | Downward | Negative |