Table 1: Overview of important publications.

PublicationPublication approachSix Sigma implementation focus areasSix Sigma methodology implementedSix Sigma tools and techniques usedSix Sigma implementation benefits

Jin et al. [19]Detailed case study on the application of Six Sigma and Lean in healthcare logisticsWarehouse managementDMADV (define, measure, analyse, design, and verification) methodology and Lean thinking principles(i) Survey
(ii) Critical to quality (CTQ) parameters
(iii) Value stream mapping
(iv) Fishbone diagram
(v) Lean thinking tools (smoothing flow and removing nonvalue-adding activities)
(i) Better storage management
(ii) Better use of space
(iii) Improved workspace
(iv) Organization and cleanliness
(v) More timely and efficient delivery of right supplies to the right patients
(vi) Tracking and reducing waste
(vii) Cost savings

Craven et al. [20]Brief case studies on the application of Six Sigma and Lean in clinical, operational, and service areas in healthcare(i) Isolation management (clinical area)
(ii) Inventory management (operational area)
(iii) Patient room turnaround time (service area)
DMAIC (define, measure, analyse, improve, and control) methodology and Lean thinking principles(i) Priority ranking for project selection
(ii) Voice of customer (VOC)
(iii) Survey
(iv) Process flow map
(v) Lean techniques (sort, straighten, sanitize, standardize, and sustain)
(vi) Cause-and-effect analysis
(i) Reduced operating expenses
(ii) Reduced patient length of stay
(iii) Improved throughput (patient flow)
(iv) Compliance and full accreditation
(v) Extended expertise
(vi) External validation through awards

Lifvergren et al. [21]Description of lessons learned from the application of Six Sigma projects in different clinical areas in healthcareHealthcare quality, patient safety, and resource utilization in different clinical areas (one of which is patients’ logistics)DMAIC (define, measure, analyse, improve, and control) methodology(i) Reducing unwanted variation in care processes
(ii) Increased patient safety
(iii) Indirect quality improvement
(iv) Optimize resource utilization
(v) Cost savings