*3.2.4 Reference model*

Through the use of the simulation software, each process studied during the previous phases was improved in order to propose most of the tools and digital technologies to increase the level of performance and security.

For this purpose, the digital flows of hospital logistics processes were simulated. First the processes were simulated separately and after implementing the optimization, they all were combined into a single simulation model. The objective of this model was to seek first the opportunities for improvement within the model, in which after stabilization it would be possible to bring them all together and make improvements to the combined logistics processes.

An example of improvement is the use of Automated Guided Vehicles (AGV) for the transportation of food from the hospital restaurant to the patients. Indeed, this action contributes to the loss of time by the nurses and caregivers.

#### **3.3 The problem-solving method**

The **Figure 6** presents the structure of the problem-solving method.

The first step of the problem-solving method is the hospital problem context acquisition. Main properties and data must be defined during this step. According to theory of systems, the description of the system will be done by finding properties associated.

**Figure 6.** *Path of the problem-solving method.*

Then, this problem will be compared to old cases contained in a capitalization database (use of case -based reasoning (CBR)). For this comparison a similitude degree will be defined. If this number is less than 0.5, it means that there are no efficient possible cases in the database.

Then, the main system transformation will be by using the reference model elaborated. If the number is between 0,5 and 0,75, both possibilities could be exploited. The cases found will be extracted from the database and the reference model will also be applied for transforming the system.

Then, if the degree is more than 0,75, only cases existing in the database will be presented to ensure the hospital flows transformation for solving problems. A decisionaided tool will be developed for managing the hospital flows digital transformation.
