The Word Bank published in 2000 this important paper we selected to post in three parts.
1 – PREAMBLE
This note proposes a more customized approach of indicators used to monitor port performance, forecast development and set targets in port sector projects. The main points are that, in most cases, it is not possible to determine benchmarks which would be applicable for any port, and that all expressions of port performance do not address the same requirements. Therefore, carefully identifying problems to be monitored and taking into account the main characteristics of the commercial activity should lead to more accurate indicators and targets.
Available data: In public ports, expressions of port performance are based on data recorded by port authorities which traditionally tend to focus on traffic recordings and parameters used in tariffing of port services. Most available and reliable data are related to the maritime interface where information is more easily collected than on the land interface. Port Authorities usually monitor berth occupancy and dwelling time of ships, characteristics of calls, performance of ship-to-shore cargo handling and availability of the main pieces of handling equipment. Additional but often less reliable data may be available as regards landward operations: dwelling time of cargo in ports’ warehouses and storage areas, characteristics of Customs and other administrative procedures and, rarely, performance of handling for pick-up and delivery goods...
Most of the time, developing a relevant set of indicators would require more information; a survey is the only way to identify whether existing data are reliable, the cause and extent of existing problems and the way they could be monitored.
Whatever criteria are chosen, they must be associated with a precise definition of what is recorded, as all port authorities do not take into account all parameters the same way; for example, they may include empty containers, shifted and transshipped boxes or the tare weight of unitized goods.
Forecast: These indicators are often used to forecast port productivity and assess future capacity.
Computerized simulation systems can give accurate estimates of berth capacity and ships’ waiting time.
Various statistical programs designed for all purpose process modeling or specialized in transportation and port logistics may be used. This note will remind of some simplifications of the queuing theory, which can give rough estimates in some simple cases.
Performance and competitiveness: These expressions of performance display mainly a technical capacity. But shippers and ship-owners have additional requirements; they are also looking for:
- Reliability: a steady and predictable performance adapted to shipping lines schedules;
- Cost: a high performance at a competitive and predictable cost;
- Quality: no overage, no wastage or pilferage or any damage registered during handling and storage operations. Progressively, producers and transporters have to comply with international standards (ISO 9000 or equivalent) and get their process certified; ports, at least those operating in a competitive environment, have to catch up with this trend;
- Adaptability: a capacity to listen to their problems and needs, negotiate and propose solutions.
A port is also a link in the transport chain and, of course, similar requirements apply as regards capacity, performance and quality of connections with short-sea and feeder shipping lines, and with inland transportation networks : road, rail, barges.
Complying with these requirements results is competitiveness and, ultimately, growing market share; ports process more traffic and shippers benefit from lower freight rates and insurance premiums. This can be assessed mainly indirectly. Fortunately, performance and competitiveness are more or less linked: high productivity is often synonymous with reliability and quality and, not systematically, with low costs.
Therefore, performance and cost targets are an acceptable approximation of competitiveness.
1.2- technical valuation of port performance
Port operations are increasingly specialized and processed in dedicated terminals but many flows of goods are still handled at general purpose berths. Depending on the case, port performance should be assessed for an homogenous set of berths or a terminal. It is usually expressed as the average number of calls and the average flow–volume or weight–of goods over a standard period of time; number of calls per berth and per year, volume or weight of cargo handled per hour, per call or per day, per gang or per crane.
In addition, other criteria can be used to see how existing capacity and performance meet the requirements of: i) the shipper or the ship-owner: mainly average waiting time of ship, dwelling time of cargo and data related to quality if possible, and: ii) of the Port Authority: basically berth occupancy rate and global traffic.
All these parameters are not equivalent:
- “snap-shot” performance (recorded during an hour, a shift, a call) describes the technical capacity of a terminal; a flow of goods recorded within a larger period depends also on parameters related to competitiveness, market share, seasonal effects, berthing capacity etc.
- Some of them are used to monitor specific points of concern for port authorities, operators or clients and cannot improve simultaneously. For example, Port Authorities are looking for relatively high berth occupancy rates whereas shippers do not accept significant waiting time.
1.3- explanatory factors
High performance is observed in private terminals and poorest performance is often associated with ports run by public Port Authorities, still in charge of cargo handling and maintenance of equipment. Beyond such a statement, explaining a poor or a good performance may require a more thorough analysis.
Exceptionally high performances occur when all parameters concur positively: as far as containers are concerned, the typical high-performing terminal is dedicated to one or a few shipping lines and privately run, processes regular and well timed calls of large ships, with economies of scale allowing it to be geared with the most high-performing gantry cranes, and handles shipments representing the major part of the ship capacity. Similar parameters can be mentioned in the case of bulk (freighted) traffic.
Conversely, in poor performing ports, many causes, often interrelated, may be mentioned:
- Physical characteristics, mainly: nautical access: dredging backlog and other factors narrowing the access time-slot; land access: ill-maintained pavements, restricted access to land-transportation networks; and port capacity: lack of berths and storage areas, insufficient room for modern ship to shore operations;
- Organizational parameters, related to ships: old ships with narrow hatches, large tween decks, slow moving derricks, spending too long idle time at berth; cargo: ill packaged, non unitized, damaged goods, organization of lashing-unlashing of containers; handling capacity: unsuitable and ill-maintained handling equipment, poorly trained work force, not enough crane drivers, unsuitable, congested and poorly managed storage areas; organization: non-productive methods, ill prepared calls, too restricted working time, unwillingness of port operators to work at night, commercial operations interfering with ship-to shore operations, excessive dwelling time of cargo for commercial motives, documentation delays; procedures: lengthy customs and other administrative procedures and controls, corruption.
Public port authorities but also other administrations, port operators, ship-owners, and shippers, involved in this process with their own objectives, may be partly responsible for these shortcomings. A rapid survey of the situation should help identify the main causes of the problems and choose adapted criteria to monitor further progress.
1.4- measuring port performances - basics
Poor performances are generally due to the organization of handling and storage operations and of maintenance. Therefore, the most common and practical way to measure port performance is to check whether organization and yard equipment can match the actual capacity of the main hoisting machines: generally quay cranes or gantries, which are the most expensive and high-performing pieces of equipment. The first step consists in determining the nominal and the optimum–or commercial–output:
- The nominal output of a crane or a gantry is the theoretical result when all parameters are optimized and reliability is absolute; it can be precisely assessed by taking into account :
. the average load to be handled:
.. break-bulk and unitized traffic: unit load plus accessories: spreaders... ;
.. dry bulk traffic : weight of buckets plus capacity x density of product,
- the average duration of a whole handling cycle (loading or unloading), taking into account the length and speed of each elementary move: hoist, translation, rotation, lowering and back to hold, with and without the load, according to the manufacturer’s technical specifications;
- The commercial output is lower; due to various factors:
. physical factors such as nautical and weather conditions impairing average performance: tide, swell, wind or rain;
. factors related to port operations: average ships’ characteristics, time spent in stowage, trimming, for opening or closing of hatch-covers, lashing-unlashing of containers, etc.
. equipment related factors: standard reliability of cranes, the time it takes to shift them, to change buckets or spreaders, and organization of work, i.e.: proportion of effective work-time during a shift;
The second step is to identify the main causes of poor performance and choosing adapted and measurable criteria.
Over a long period of time, additional delays must be deduced from the commercial output to take into account the extra time spent by ships when they are berthed, before and after commercial operations, waiting for various motives: due to nautical and weather constraints, because of locks or swaying bridges, waiting for port services (bunkerage, repairs), because of non flexible working time.
Benchmark: Most container gantry cranes have a theoretical output of 35 to 40 moves per hour or more. The commercial output, depending on local conditions, varies usually from 15 to 35 in average, with peak performance nearing theoretical performance.
The Delta Sea-Land Terminal at Rotterdam has recently invested in double-trolley gantry cranes and a fully integrated and automatized system between ships and stacking areas which is intended to reach 50 TEUs per hour and per hold, i.e., almost doubling the usual output.
In the case of continuous handling of bulk products, the commercial performance may be closer to the theoretical output (80 to 90 %) with peak performance exceeding theoretical performance, depending on the reliability of equipment and the characteristics and number of products to be handled during a call.
As far as the performance of the land interface is concerned, the problem is generally the lack of data;
- Average cargo dwelling time. A distinction should be drawn between the impact of customs and other administrative procedures, of shortcomings in storage management and cargo handling, and of commercial practices (e.g., when port storage is less expensive than private warehousing). The average dwelling time should not exceed 5 days for containers, 7 to 10 days for general cargo, two weeks for bulk products.
Commercial constraints may lead to longer delays.
- the average time spent by a trailer waiting for its load to be located, handled, and to get its clearance, is usually known only through occasional surveys, even though pick-up and delivery of goods often accounts for a large part of the port congestion and inefficiency. It should not exceed 4 to 6 hours. 2 hours are the norm in modern container terminals.
Regarding equipment reliability, two parameters must be identified: i) the reliability in operation, i.e., the number and length of breakdowns occurring during commercial operations and: ii) the average availability, after deduction of planned maintenance and all breakdowns.
For small pieces of equipment like tractors, trailers, forklifts, availability should be very high (95 % or higher), provided that their number matches the demand and standard preventive maintenance is performed.
Regarding gantries, cranes, RTGs, breakdowns may occur and stop port operations; with normal preventive maintenance, most of them should be limited to electricity and automation problems and repaired within a few hours. Availability should be more than 90 %. The norm in modern terminals is close to 98 %, or 2% unscheduled downtime. An occasional lack of gantry-cranes drivers may reduce the above availability; this parameter is not always identified.
Next post: Part II will continue.
