TY  - JOUR
AU  - Milašinović, Miloš
AU  - Ivetić, Damjan
AU  - Stojković, Milan
AU  - Savić, Dragan
PY  - 2023
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/3034
AB  - Climate change, energy transition, population growth and other natural and anthropogenic impacts, combined with outdated (unfashionable) infrastructure, can force Dam and Reservoir Systems (DRS) operation outside of the design envelope (adverse operating conditions). Since there is no easy way to redesign or upgrade the existing DRSs to mitigate against all the potential failure situations, Digital Twins (DT) of DRSs are required to assess system’s performance under various what-if scenarios. The current state of practice in failure modelling is that failures (system’s not performing at the expected level or not at all) are randomly created and implemented in simulation models. That approach helps in identifying the riskiest parts (subsystems) of the DRS (risk-based approach), but does not consider hazards leading to failures, their occurrence probabilities or subsystem failure exposure. To overcome these drawbacks, this paper presents a more realistic failure scenario generator based on a causal approach. Here, the novel failure simulation approach utilizes fuzzy logic reasoning to create DRS failures based on hazard severity and subsystems’ reliability. Combined with the system dynamics (SD) model this general failure simulation tool is designed to be used with any DRS. The potential of the proposed method is demonstrated using the Pirot DRS case study in Serbia over a 10-year simulation period. Results show that even occasional hazards (as for more than 97% of the simulation there were no hazards), combined with outdated infrastructure can reduce DRS performance by 50%, which can help in identifying possible “hidden” failure risks and support system maintenance prioritization.
PB  - Springer Link
T2  - Water Resources Management
T1  - Failure Conditions Assessment of Complex Water Systems Using Fuzzy Logic
DO  - 10.1007/s11269-022-03420-w
ER  - 

@article{
author = "Milašinović, Miloš and Ivetić, Damjan and Stojković, Milan and Savić, Dragan",
year = "2023",
abstract = "Climate change, energy transition, population growth and other natural and anthropogenic impacts, combined with outdated (unfashionable) infrastructure, can force Dam and Reservoir Systems (DRS) operation outside of the design envelope (adverse operating conditions). Since there is no easy way to redesign or upgrade the existing DRSs to mitigate against all the potential failure situations, Digital Twins (DT) of DRSs are required to assess system’s performance under various what-if scenarios. The current state of practice in failure modelling is that failures (system’s not performing at the expected level or not at all) are randomly created and implemented in simulation models. That approach helps in identifying the riskiest parts (subsystems) of the DRS (risk-based approach), but does not consider hazards leading to failures, their occurrence probabilities or subsystem failure exposure. To overcome these drawbacks, this paper presents a more realistic failure scenario generator based on a causal approach. Here, the novel failure simulation approach utilizes fuzzy logic reasoning to create DRS failures based on hazard severity and subsystems’ reliability. Combined with the system dynamics (SD) model this general failure simulation tool is designed to be used with any DRS. The potential of the proposed method is demonstrated using the Pirot DRS case study in Serbia over a 10-year simulation period. Results show that even occasional hazards (as for more than 97% of the simulation there were no hazards), combined with outdated infrastructure can reduce DRS performance by 50%, which can help in identifying possible “hidden” failure risks and support system maintenance prioritization.",
publisher = "Springer Link",
journal = "Water Resources Management",
title = "Failure Conditions Assessment of Complex Water Systems Using Fuzzy Logic",
doi = "10.1007/s11269-022-03420-w"
}

Milašinović, M., Ivetić, D., Stojković, M.,& Savić, D.. (2023). Failure Conditions Assessment of Complex Water Systems Using Fuzzy Logic. in Water Resources Management
Springer Link..
https://doi.org/10.1007/s11269-022-03420-w

Milašinović M, Ivetić D, Stojković M, Savić D. Failure Conditions Assessment of Complex Water Systems Using Fuzzy Logic. in Water Resources Management. 2023;.
doi:10.1007/s11269-022-03420-w .

Milašinović, Miloš, Ivetić, Damjan, Stojković, Milan, Savić, Dragan, "Failure Conditions Assessment of Complex Water Systems Using Fuzzy Logic" in Water Resources Management (2023),
https://doi.org/10.1007/s11269-022-03420-w . .

TY  - JOUR
AU  - Ignjatović, Lazar
AU  - Stojković, Milan
AU  - Ivetić, Damjan
AU  - Milašinović, Miloš
AU  - Milivojević, Nikola
PY  - 2021
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/2454
AB  - The objective of this research is to introduce a novel framework to quantify the risk of
the reservoir system outside the design envelope, taking into account the risks related to floodprotection and hydro-energy generation under unfavourable reservoir element conditions (system
element failures) and hazardous situations within the environment (flood event). To analyze water
system behavior in adverse conditions, a system analysis approach is used, which is founded
upon the system dynamics model with a causal loop. The capability of the system in performing
the intended functionality can be quantified using the traditional static measures like reliability,
resilience and vulnerability, or dynamic resilience. In this paper, a novel method for the assessment
of a multi-parameter dynamic resilience is introduced. The multi-parameter dynamic resilience
envelops the hydropower and flood-protection resilience, as two opposing demands in the reservoir
operation regime. A case study of a Pirot reservoir, in the Republic of Serbia, is used. To estimate
the multi -parameter dynamic resilience of the Pirot reservoir system, a hydrological model, and a
system dynamic simulation model with an inner control loop, is developed. The inner control loop
provides the relation between the hydropower generation and flood-protection. The hydrological
model is calibrated and generated climate inputs are used to simulate the long-term flow sequences.
The most severe flood event period is extracted to be used as the input for the system dynamics
simulations. The system performance for five different scenarios with various multi failure events
(e.g., generator failure, segment gate failure on the spillway, leakage from reservoir and water supply
tunnel failure due to earthquake) are presented using the novel concept of the explicit modeling of the
component failures through element functionality indicators. Based on the outputs from the system
dynamics model, system performance is determined and, later, hydropower and flood protection
resilience. Then, multi-parameter dynamic resilience of the Pirot reservoir system is estimated and
compared with the traditional static measures (reliability). Discrepancy between the drop between
multi-parameter resilience (from 0.851 to 0.935) and reliability (from 0.993 to 1) shows that static
measure underestimates the risk to the water system. Thus, the results from this research show that
multi-parameter dynamic resilience, as an indicator, can provide additional insight compared to the
traditional static measures, leading to identification of the vulnerable elements of a complex reservoir system. Additionally, it is shown that the proposed explicit modeling of system components failure
can be used to reflect the drop of the overall system functionality
PB  - MDPI
T2  - Water
T1  - Quantifying Multi-Parameter Dynamic Resilience for Complex Reservoir Systems Using Failure Simulations: Case Study of the Pirot Reservoir System
IS  - 22
VL  - 13
DO  - 10.3390/w13223157
ER  - 

@article{
author = "Ignjatović, Lazar and Stojković, Milan and Ivetić, Damjan and Milašinović, Miloš and Milivojević, Nikola",
year = "2021",
abstract = "The objective of this research is to introduce a novel framework to quantify the risk of
the reservoir system outside the design envelope, taking into account the risks related to floodprotection and hydro-energy generation under unfavourable reservoir element conditions (system
element failures) and hazardous situations within the environment (flood event). To analyze water
system behavior in adverse conditions, a system analysis approach is used, which is founded
upon the system dynamics model with a causal loop. The capability of the system in performing
the intended functionality can be quantified using the traditional static measures like reliability,
resilience and vulnerability, or dynamic resilience. In this paper, a novel method for the assessment
of a multi-parameter dynamic resilience is introduced. The multi-parameter dynamic resilience
envelops the hydropower and flood-protection resilience, as two opposing demands in the reservoir
operation regime. A case study of a Pirot reservoir, in the Republic of Serbia, is used. To estimate
the multi -parameter dynamic resilience of the Pirot reservoir system, a hydrological model, and a
system dynamic simulation model with an inner control loop, is developed. The inner control loop
provides the relation between the hydropower generation and flood-protection. The hydrological
model is calibrated and generated climate inputs are used to simulate the long-term flow sequences.
The most severe flood event period is extracted to be used as the input for the system dynamics
simulations. The system performance for five different scenarios with various multi failure events
(e.g., generator failure, segment gate failure on the spillway, leakage from reservoir and water supply
tunnel failure due to earthquake) are presented using the novel concept of the explicit modeling of the
component failures through element functionality indicators. Based on the outputs from the system
dynamics model, system performance is determined and, later, hydropower and flood protection
resilience. Then, multi-parameter dynamic resilience of the Pirot reservoir system is estimated and
compared with the traditional static measures (reliability). Discrepancy between the drop between
multi-parameter resilience (from 0.851 to 0.935) and reliability (from 0.993 to 1) shows that static
measure underestimates the risk to the water system. Thus, the results from this research show that
multi-parameter dynamic resilience, as an indicator, can provide additional insight compared to the
traditional static measures, leading to identification of the vulnerable elements of a complex reservoir system. Additionally, it is shown that the proposed explicit modeling of system components failure
can be used to reflect the drop of the overall system functionality",
publisher = "MDPI",
journal = "Water",
title = "Quantifying Multi-Parameter Dynamic Resilience for Complex Reservoir Systems Using Failure Simulations: Case Study of the Pirot Reservoir System",
number = "22",
volume = "13",
doi = "10.3390/w13223157"
}

Ignjatović, L., Stojković, M., Ivetić, D., Milašinović, M.,& Milivojević, N.. (2021). Quantifying Multi-Parameter Dynamic Resilience for Complex Reservoir Systems Using Failure Simulations: Case Study of the Pirot Reservoir System. in Water
MDPI., 13(22).
https://doi.org/10.3390/w13223157

Ignjatović L, Stojković M, Ivetić D, Milašinović M, Milivojević N. Quantifying Multi-Parameter Dynamic Resilience for Complex Reservoir Systems Using Failure Simulations: Case Study of the Pirot Reservoir System. in Water. 2021;13(22).
doi:10.3390/w13223157 .

Ignjatović, Lazar, Stojković, Milan, Ivetić, Damjan, Milašinović, Miloš, Milivojević, Nikola, "Quantifying Multi-Parameter Dynamic Resilience for Complex Reservoir Systems Using Failure Simulations: Case Study of the Pirot Reservoir System" in Water, 13, no. 22 (2021),
https://doi.org/10.3390/w13223157 . .