## 4 Conclusions  
The testing and evaluation of a smart logistics system was carried out in order to identify functional limitations and important improvements to be implemented. The functional features of the smart box and centralized information platform were considered during testing. The features were designed to enable users to have an effective information acquisition, monitoring, and utilization system while promoting sustainable pruning for the energy value chain. All three smart box prototypes were tested together with the information platform. Based on tests done in Spain, Germany, and Sweden, the performance evaluation of the smart system was carried out by systematically analyzing:  
* values of parameters recorded and stored in the spreadsheet database with 41 columns (for each pruning product registered with a specific lot number),
* feedback and problems encountered during the test, and
* selected performance metrics in relation to product quality model adapted from ISO/IEC FDIS 9126-1 standard.  
The performance test results indicate that the smart system satisfactorily performed data collection and storage in the central database. The stored data and other relevant information enabled the tool to support product traceability and supply chain management very effectively.  
In general, for each batch of pruning biomass (with specific lot number) entering and leaving the biomass supply chain, data entered into the online platform directly by actors (farmers, traders, etc.) were well documented in the central database and easily visualized by intended users. The information platform enabled users to display the locations of pruning farms, biomass storage and processing sites, energy plants, and the planned and/or actual delivery routes according to the needs of different actors, such as raw materials producers, traders, and consumers. However, some errors were noticed regarding the smart box identification numbers (expected to be transferred from the smart box to the central database during product pickup and delivery), product delivery codes (expected to be generated by the smart system), and product pickup and delivery times. These errors might have been caused by improper initialization (while triggering the smart box with a power scan), unplugging the power cables before data transmission was complete, or unexpected barriers that interrupted data transmission from the smart box to the online platform. To counteract these problems and increase information continuity along the pruning supply chain as well as effective utilization of the smart system, additional functional features should be created so that transporters and consumers can confirm product delivery and acceptance, respectively. This option enables retrieval of important information that could be missed due to problems encountered by the smart box during data transfer to the central database and increases system performance so that it can be upgraded to a marketable tool promoting sustainable biomass development for renewable energy generation.  
[PERSON] and [PERSON] conceptualized the validation the SLS. [PERSON], [PERSON], [PERSON] and [PERSON] designed the methodology of performance evaluation of SLS. [PERSON], [PERSON], [PERSON], and [PERSON] participated in field test activities, monitoring and providing feedback for the development of SLS. [PERSON] wrote the paper while [PERSON] reviewed it.  
This research was funded by the European Union Seventh Framework Programme (FP7/2007-2013), grant number 312078. This work was part of international EuroPruning project, \"Development and implementation of a new and non-existent logistics chain for biomass from pruning\".  
**Conflicts of Interest:** The authors declare no conflict of interest.