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Analyzing the Interconnected Factors That Determine Port Efficiency 2023-02-17

Analyzing the Interconnected Factors That Determine Port Efficiency

- Influence analysis of Berth Waiting Ratio & Berthing schedule compliance rate on port/terminal productivity 

Among the port/terminal productivity indicators presented by UNCTAD and the World Bank, berth waiting ratio and berth occupancy rate are included. As per CyberLogitec’s influence analysis of Berth Waiting Ratio(BWR), Berth Occupancy Ratio(BOR), and Time Difference of Berthing(TDB) between planned berthing time and actual berthing time on terminal/port productivity based on the collected data from current operating terminal using OPUS Terminal, it’s been found that changes in BWR and berthing schedule compliance rate result in a significant impact on the productivity.


Port Berthing & Working Time-wise Indicator


Among the newly developed services related to AI technology at the terminal, there’s a provided service regarding Berth ETB (Estimated Time of Berthing). 

As the difference increases between ETB and ATB (Actual Time of Berthing), it will decrease the terminal productivity and change BOR (Berth Occupancy Ratio).  

Hence, many terminals are developing services to predict accurate ETB recently. 

1. Berth Waiting Rate (BWR) and STS Productivity 

Berth Waiting Rate is a service competitiveness index of berths at ports and terminals. According to UNCTAD, it is recommended to maintain BWR below 30%. As per OECD, the exemplary BWR is 10%. The average BWR for A terminal is 32.21%, and its BWR states the decreasing tendency as the vessel’s work volume increases. 

*UNCTAD = United Nations Conference on Trade and Development

▷Relationship between Berth Waiting Ratio(BWR) & Productivity

STS productivity has to decrease tendency as BWR increases. The tendency is more apparent when work volume exceeds 2,000 VAN, as per A terminal case study.


2. Schedule Compliance Rate for Vessel

TDB (Time Difference of Berthing) is the time difference between the estimated time of berthing(ETB) and the actual time of berthing (ATB) for a vessel. The schedule compliance rate for a vessel can be calculated by using TDB between ETB & ATB. By setting the TDB tolerance range to 40min, 60min, and 120min, the Effect of ETB compliance rate on the terminal’s productivity can be found by comparing STS productivity when TDB is within the tolerance range and TDB is out of the tolerance range. 

TDB tolerance range-wise schedule compliance rate
  - TDB tolerance range (40min) – 10.4% of all vessels are out of ETB
  - TDB tolerance range (60min) – 2.96% of all vessels are out of ETB
  - TDB tolerance range (120min) – 0.57% of all vessels are out of ETB

As per the vessel’s productivity comparison between a vessel within ETB and a vessel out of ETB, the TDB tolerance range below 40min has a low impact on productivity, yet the TDB tolerance range above 60min decreases productivity in proportion to the time difference.
When TDB is set to 40 minutes, the productivity of the vessel out of ETB is reduced by 6.5%, 7.3% for TDB 60 minutes, and 28% for TDB 120 minutes. 


Berth Waiting Ratio (BWR) according to the vessel’s schedule compliance rate

When the loading/unloading work volume is above 2,000 VAN(BOX) and TDB between the estimated time of berthing and the actual time of berthing is more than 40 minutes, there is a significant increase in Berth Waiting Time (BWT). 


3. Berth Occupancy Ratio (BOR) & Productivity 

Berth Occupancy Rate derives from the vessel’s service time and berth information. Herein, it is calculated based on the number of working days per month (No off, 365 days per year applied). According to the terminal operation policy, berth operation time is generally 360 to 365 days per year.

If Berth Occupancy Ratio (BOR) is too high, there’s a high possibility that vessel congestion will occur hence which would lead to an increase in Berth Waiting Time (BWT). Otherwise, the equipment productivity decreases when BOR is low. 
The average Berth Occupancy Rate (BOR) for the berths in the entire A terminal is 70.4%. 

Berth Occupancy Ratio and STS Productivity 
The average Berth Occupancy Ratio (BOR) of the entire berths is 70.4%, and the average STS productivity is 18.81 VAN. Berth productivity with more than 80% of BOR is 17.8 VAN which is 94.6% of average STS productivity. Comparing the productivity between ‘Above BOR’ and ‘Below BOR’, productivity decreases by 8.39% in the ‘Above BOR’ case based on the BOR standard of 80%.

Berth’s STS productivity with more than 80% BOR decreases by less than 5% compared to average productivity.

Berth Waiting Ratio(BWR), Time Difference of Berthing(TDB), and Berth Occupancy Ratio(BOR) differ depending on vessel size, vessel volume, and shipping liners. Hence, each operating terminal is suggested to derive BWR, TDB, and BOR for establishing operation strategy and improving optimized logic.

OPUS Terminal considers the factors mentioned above to predict terminal operation and provides services that improve productivity. 
The followings below are the result of customer terminal A’s data analysis.

STS productivity drops by 6.5% when the time difference between ETB and ATB(TDB) is more than 40 minutes and by 28% when it is more than 120 minutes. 
To meet the Estimated Time of Departure(ETD), the Terminal operation team and its operating system could establish a strategy to input additional STS and share newly updated ETD to the shipping liner when scheduled vessel for work delays in berth.

Also, productivity decreases by 8.39% when BOR is above 80% in terminal A. Berth planning should be consider reduced productivity.

The value differs as per the terminal-wise berthed vessel size, throughput and operation condition, hence the strategy to apply the analyzed data immediately and systemically is needed instead of its generalized application.

STS productivity is an operational result as well as significant reference value to establish terminal operation strategy. Based on historical STS Productivity, the terminal decides how many Yard Trucks, Yard Cranes and Gangs(Workers) to input for each vessel as well as its working time and calculates Estimated Time of Departure(ETD) for the vessel.

At the time of establishing operation strategy in view of STS productivity, considering the change in productivity according to TDB between ETB & ATB, and BOR values, a more accurate Estimated Time of Work (ETW) can be calculated, which can contribute to higher productivity by TOS logic optimization.

Author: Lucy (Kyoung-Suk) Lee, Terminal Business Consultant, CyberLogitec

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