Abstract

Jones C, Dodds S. Improving the Delivery of Chemotherapy: Part 6. Using Complex Physical System Modelling and Re-Design to Restore the Calm. Journal of Improvement Science 2019: 62; 1-22.

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Rising demand for systemic anti-cancer therapy (SACT) in Swansea Bay University Health Board (SBUHB) is putting growing pressure on existing services including the chemotherapy day unit (CDU) at Singleton Hospital.

Five previous pieces of work have been completed. The first three tackled different flow constraints within the process and improved the flow to the unit, and the next two concentrated on collecting data of good enough quality to allow modelling of the flow within the unit. Our next task was to investigate the multiple sources of variation inherent within our system in far more detail in order to better understand what was causing them and to design them out of the process.

Advanced health care systems engineering (HCSE) techniques and tools were employed to address the "diagnosis" block that was thwarting progress. A verified complex physical system (CPS) flow simulation model of the Singleton CDU was used to explore possible causes that were limiting the maximum activity. These included; lack of chair capacity, lack of staff capacity, and patient and staff scheduling design as well as other causes that are often present but are difficult to see.

The diagnostic modelling suggested that the dominant cause of the queues, delays and chaos was the current policy of allocating patients to pre-designated rooms, chairs and staff according to the duration of their treatment. This is called a capacity carveout design.

With this focus the CDU team were able to design a modified scheduling policy and the CPS model allowed us to assess the impact of the design change in a controlled environment before implementing our changes in the safety critical real-world.

A one-day test-of-change was conducted by the CDU staff which confirmed the CPS model predictions: The feeling of chaos was converted to a sense of calm that was immediately obvious to staff and patients.

The impact was so profound that the CDU staff voted to implement the design change the following week.

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Cancer; Carveout; Chemotherapy; Complex Physical System (CPS); Diagnostic Modelling; Flow Constraint; Health Care Systems Engineering (HCSE); Healthcare; Pilot Study; Quality of Work Life (QoWL); Stream Level Design; Systemic Anti-Cancer Treatment (SACT); Variation