From push to pull

Pathology units processing thousands of samples a day can easily reach breaking point, but how can the backlog be overcome? We look to the Leicester Royal Infirmary Pathology Department and find out the answer is making the move from ‘push’ to ‘pull’

A review of specimen reception and preliminary sample handling using Lean principles has led to improvements in the processing of a daily workload of 11,000 samples at the Leicester Royal Infirmary (LRI) Pathology Department.

The sample process step that used to take four and a half hours has been reduced to 20 minutes, and a previous build up of up to 1,000 samples at any given time has been eliminated entirely. What used to be a chaotic and difficult-to-manage ‘push’ workflow is now an organised and simple ‘pull’ workflow.  

Through the application of Lean principles, the laboratory has been able to create a more efficient workflow to meet both its high throughput demand and NHS targets. Furthermore it has been able to redesign its procedures to make better use of the automation capabilities of the ADVIA LabCell Automation Solution. By smoothing the flow of samples though the laboratory, LRI has been able to optimise the use of its automation capabilities, freeing up resources for sample management and other tasks.

Anne Freestone, Blood Sciences Laboratory Manager at Leicester Royal Infirmary said: “Lean working is all about being flexible, open to change, and making more efficient use of existing resources to improve workflow and minimise waste. We were early adopters of recommendations from the Carter and Darzi reports and pathology testing services were centralised at Leicester Royal Infirmary, consolidating cold work from the Glenfield and Leicester General Hospitals.”

The move to Lean working at the LRI Pathology Department was initiated by a Managed Pathology Services contract with Siemens to provide an effective, efficient pathology service to the Trust. This agreement saw the installation of an ADVIA LabCell automation system, which effectively combines clinical chemistry, immunoassay, haematology and haemostasis into a single solution. However it soon became clear that automation alone was not the solution to the laboratory’s workflow issues. The workload was overwhelming, particularly in the combined specimen reception area and not surprisingly, staff morale was low.

Adequate capacity was ensured with the ADVIA LabCell and connected analysers. Through Lean analysis, the extent of the bottleneck was identified. A real sticking point was the timing of the high volume, non-urgent work that flooded in relatively late in the working day from the 180 GPs served by the department. Despite up to 20 staff members booking in and sorting the requests, samples were still not being transferred to the laboratory analysers in a timely fashion. At the same time, the department still had to meet its guaranteed one-hour turnaround time for acute units such as A & E and ITU.

After a preliminary process review, Siemens trained a team of six LRI staff members to evaluate the situation in detail, using Lean methodology.

Spaghetti mapping followed an ‘average’ sample on its path through the department, identifying the actions required for each sample, as well as tracking the movement of the sample around the laboratory. This technique highlighted that samples were undergoing approximately 12 to 14 separate processing steps. Due to the backlog of samples at any given processing station, this meant that there could be in excess of 1,000 samples awaiting completion at any one time.

Similar to spaghetti mapping, value stream mapping followed an ‘average’ sample through the laboratory system, timing each stage and comparing ‘touch times’ – where the sample was actually being handled – with the waiting times between stages. The evaluation established that the average sample took:
• Four and a half hours to pass through the laboratory processes
• 12 minutes of active processing
• 4 hours 18 minutes of idle time awaiting further action

“This information was not a great surprise to us; the staff had spent the previous few years firefighting this issue and could now see exactly where the problems lay,” said Freestone, “Together, these tools supported the ideal of one stream of work and emphasised the importance of accurately measuring processes, rather than making assumptions. The ‘Lean team’ used the resulting information to devise a pilot project and to communicate these ideas to their initially sceptical colleagues.”

To reduce the movement of individual staff members around the laboratory, a ‘sweeper’ system was used. A designated ‘sweeper’ would regularly go around the workcells every ten minutes, picking up the samples, spinning them down and sending them up to the lab. This not only simplified sample logistics within the laboratory, but also created a steady stream of samples to the analysis track.  

Levelling the workflow also improved the efficiency of downstream processing and analysis, allowing the ADVIA LabCell to operate at higher throughput for a more prolonged period around peak times, without exceeding the platform’s capacity.  

Alongside the pilot project, a new colour was introduced to the GP surgeries’ coloured bag system, effectively pre-sorting all samples that required U&E profiles, so that all time-sensitive samples were given priority. This assisted with sample integrity and has also helped the lab to track samples almost as soon as they reach the pathology building. Similarly, a ‘first in, first out’ system has been established so that samples arriving are put into numbered boxes and dealt with in order of arrival.

Implementation of the initial Lean process took approximately six months, dramatically changing the workflow of the laboratory. Inevitably, there was some initial resistance to change but this was overcome with the encouragement of colleagues in the Lean team.

Freestone said: “This new approach has changed the overall outlook of the laboratory; processes are continually re-evaluated and a whole ethos of change and innovation has taken hold. It was invaluable to have Siemens Health Care Solutions as a neutral, independent partner, looking at the laboratory with a fresh eye, sharing experiences from other laboratories and supporting the Lean team throughout the process.”