Finding the Waste: Parts Inventory Analysis Using Lean Methodology

Abstract

During a 12-year period (2011-23), the number of staff in the Clinical Engineering (CE) Department at the Children's Hospital of Eastern Ontario (CHEO) increased from five to more than 20 biomedical equipment technicians/technologists. However, despite this increase in staff, processes did not evolve and procedures that used modern technological and shipping advances were not implemented. The absence of standardized procurement and inventory processes for parts created discrepancies between on-hand inventory and the computerized maintenance management system (CMMS). Owing to inaccurate CMMS information and unsystematic parts documentation, time and money were wasted. This situation led to a lack of confidence in CMMS data, causing staff disengagement, loss of accountability, and limited parts tracking. The current article describes a project that used Lean methodologies and use of the define, measure, analyze, improve, and control structure, including tools such as interviews, a survey, process mapping, and Gemba walks, to create a list of prioritized problems. A total of 16 problems were formulated, four of which were identified as prerequisites to be implemented regardless of prioritization. The four prerequisites described the scope of each problem and potential solutions. The goal of this process was to create a workflow that could save time and money while improving the morale of stakeholders involved in the parts procurement and inventory process.

Figure 1

Biomedical equipment technicians/technologist (BMET) role in preordering stage. This figure represents a subsection of the process map that was created through the Lean exercise. Abbreviations used: CMMS, computerized maintenance management system; SC, service call.

Figure 2

Parts inventory in CMMS from April 2011 to March 2023. Percent differences: between B and C, 31.8%; between D and E, 49.1%; between F and G, 24.2%; between H and I, 26.0%; between J and K, 34.4%.

Figure 3

Weighted average of survey results.

Figure 4

Driver diagram illustrating prerequisite processes. Abbreviations used: CMMS, computerized maintenance management system; SOP, standard operating procedures.

Figure 5

Driver diagram representing suggested solutions of five themes of parts-ordering issue. The solutions to the problems were identified through the focus groups. In certain cases, the same solution (column 3) was proposed for multiple problems (column 2). In the driver diagram, the solutions are color coded to represent the problem and theme that it solves. For example, the solution of “build resource library” solves all three problems under the theme of “staff: education and training” and the problem of “lack of documentation” under the computerized maintenance management system (CMMS) theme.