“Choosing a wearable safety system: cost and performances”
 

ARIANNA, in the frame of the PROTECT project (co-funded by the European Commission), after the quantitative and qualitative output of the assessment of the requirements and constraints, analyses the cost-effectiveness of a localisation and tracking system in GPS-denied environment.

 

The study provides a sound confirmation that the major objective of the system scale-up toward a market-ready system is NOT the complete fulfilment of all the possible requirements coming from all the practitioners and stakeholders, but a system design capable of representing the better suited trade-off between the cost/performance of the system and the fulfilment of the requirements relevant to the major percentage of the risky situations.

 

The Figure 1 illustrates, in a indicative quantitative way, the different “market” impact of the two possible ways of fulfilling the requirements provided by the end-users.

1. Blue plot: the system is designed to cope with the operational scenarios; this should be in line with the expectations of the practitioners, because their “ideal” target should be to have a performing system, independent of the specific intervention scenario.

2. Orange plot: the system is designed to cope with the scenarios associated with the most risky situations, which are a subset of all the possible scenarios; this should be in line with the cost-effectiveness of the system, pursued by the customers, because such a system is actually needed if and where a risky situation can jeopardise the operations and can provide a boost of the situational awareness, if and where needed, but not when is not needed.

 

On one hand, a design capable of coping with all the possible scenarios would have a cost very rapidly increasing with the percentage of the fulfilled scenarios; for instance, as far as the operators walk, the relevant scenarios can be fulfilled by a 0.5 k€ system, but the cost would rise to 10 k€, if we want a system also performing when the operator swims or skates. It is apparent that, above a certain threshold, there is no market for the system, because it will exceed the purchase capabilities of the customers.

 

The Figure 2 shows the weighted risk level associated with the typical movements performed during the operations; from that analysis, the Table 1 has been elaborated, showing that the movements already managed by ARIANNA (indicated as green lines in the table) can already face 83.6% of all the “risk normalised” movements; in addition, with the ongoing system improvements, can handle an additional 10.6% (use of ropes and platform lifts), achieving the capability of handling the 94.2% of the risky cases.

 

The above evaluation is in line with the achievement of a system performing in the highest possible percentage of the risky scenarios, meanwhile keeping the system cost below the expenditure capabilities of the customers.