The search for increased productivity prompted HPH's Port of Felixstowe to look more closely at the scheduling and operational integration of its terminal tractor fleet. A joint project with PA Consulting Group, an international management, systems and technology consulting firm, has resulted in a system that is now at the leading edge of real-time scheduling technology, project leader Iain Maclean explains.
When we were first called in to the Port of Felixstowe, I had little experience of port operations. The brief was to optimise the Port's resources with a view to increasing throughput, without increasing the terminal tractor fleet, or the number of quay cranes. It didn't take me long to discover that a tug (the local term for a terminal tractor) was not something that worked on water.
The PA team started in November 2000, co-operating closely with a team drawn from the port's operations and IT personnel. Even though our team was not specialist in ports, and we had much to learn about their business, the two teams quickly became one (especially after the lottery syndicate was created!).
The system we created together was commissioned at the Port of Felixstowe in May and June last year. It was designed, developed and implemented using industry best practice, and I regard it as PA's finest accomplishment to date in the area of complex scheduling.
The Port of Felixstowe, of course, is more interested in its operational performance. According to Chris Lewis, Felixstowe's IT Director, "the Tug Scheduling System has significantly improved efficiency by maximising the use of existing resources. This has avoided additional investment in expensive machinery".
Currently handling about two million containers a year, the Port of Felixstowe is the UK's largest container port. To maintain that position, Felixstowe aimed to deliver greater efficiency by increasing the throughput of the quay cranes , without increasing the level of resource that is currently used to service each crane, as this would directly increase costs.
After an initial assessment of the Port's operations it was found that the limiting factor was not due to the performance capability of the quay cranes, but instead, inefficienies in using the tugs serving those cranes. Now, following the implementation of a real-time Tug Scheduling System (TSS) the port is able to schedule its quay cranes and tugs more efficiently, allowing it to handle significantly increased throughput without any extra equipment or resources. The system also helps to monitor and control terminal operations more effectively by providing accurate and up-to-date information to vessel controllers and managers.
Problem solving
Previously, a number of vessel controllers were responsible for tug operations at the Port, each managing around 25 tugs. This was done via radio, communicating instructions to tug drivers on which containers to pick up, where to pick up and where to unload. It was the vessel controllers' responsibility to ensure that operational, health and safety, and timing constraints were observed, but this was difficult to manage effectively due to the large traffic volume and the high number of variables.
Once the controller had decided a course of action, instructions were issued to the relevant tug drivers. Whilst doing this, the controller had to keep track of all of the tugs and containers under their responsibility. This is a continuous process that required the control to react to frequent changes and unexpected events, such as tugs breaking down, and the wrong boxes going to the wrong tugs.
Three factors had to be considered in order to develop the system. Firstly, the system had to be able to schedule work in an efficient manner based on the variables and constraints of port operations, and also be able to react to, and schedule around, unexpected events in a sensible way. Secondly, the system had to be able to deliver instructions directly to the tug, quay crane and gantry crane drivers, minimising the need for vessel controllers to communicate instructions via radio. Thirdly, information must be fed back to the vessel controller and operations manager regarding the current state of containers and tugs. All of this had to happen in real-time.
The size, complexity and the real-time nature of this scheduling problem made it a truly challenging task.
The Tug Scheduling System software was developed to integrate with existing Port systems to deliver real-time scheduling, monitoring and control of tugs. At the core of the system is Real-Time Optimal Complex Scheduling technology (ROCS), designed and developed by PA Consulting Group to allow the real-time computation of such highly complex problems. The visualisation of the system was achieved using ILOG ViewsTM and enables the controllers to absorb schedule information quickly.
To ensure schedules were practical, PA worked closely with operations managers, vessel controllers and tug drivers from the Port to generate a set of constraints and scheduling rules. This involved a huge amount of data gathering, such as finding out which drivers had which type of permit for container handling; calculating the travel times to and from every location in the port; and observing operations to see how unexpected situations were handled.
Using a specially designed test room, the combined PA and Port of Felixstowe team was able to develop, integrate and test a scheduling system that was capable of scheduling all of the tugs across the Port. The new system means that tug drivers are now guaranteed to receive a fully assessed response to questions or instructions within 10 seconds - typically, a response is within five seconds.
The TSS uses radio data telemetry to monitor movement of containers and transmit new schedules. Any change to a current schedule causes TSS to re-schedule and send any new instructions to in-cab displays that are mounted in each of the tugs. The system is viewed via a graphical tool, specifically designed to help the vessel controller gain greater visibility of all activities within the domain for which they are responsible. The vessel controller uses the tool to monitor progress, allowing overall management of load and discharge of a vessel in order to decrease turnaround times.
Taking control
The implementation of TSS began at Felixstowe in November 2000, initially scheduling four quay cranes and 20 tugs. By mid-July 2001, the system was operational 24 hours a day, and deployed across the Port.
Beyond the basic scheduling of containers, TSS is able to accommodate and schedule special equipment and implement best operational practices including the scheduling of tugs with multiple trailers, and the scheduling of twinpick-enabled cranes. The system plans for "look ahead" so that tugs are sent ahead to get distant boxes that must be loaded between two closer boxes, and allows the scheduling of tugs across a group of cranes, as well as dual cycling, which allows boxes taken from a tug for loading to be immediately replaced with boxes bound for the container parks.
The TSS increases information flow and visibility on the Port, by allowing vessel controllers to reference information on both tug drivers and equipment. It can be used to adjust certain scheduling constraints and settings, allowing the controller to modify the way the schedules are generated in order to increase throughput.
The system also enables closer monitoring and controls operation so that the positive or negative impacts of any operational or scheduling changes can be fully assessed.
TSS is a world-first in port scheduling; it has allowed the Port of Felixstowe to achieve significantly increased throughput without investing in additional expensive handling equipment. Importantly, it also increases the safety of Port employees by ensuring rules are not broken, and has effectively eradicated "lost container" problems.
Information for terminal management: the schedule monitoring and control graphical user interface (GUI).
