In addition to automating the paper system, the accomplishment of the passive tracking phase is to achieve accurate inventory control. Accurate passive tracking is a base requirement if the computer is to participate in the management of the container terminal. To understand the computer directed operation, the computer should be pictured as an enormously capable group of people locked in a windowless room with a telephone for outside contact. The group receives information about the container terminal only over the telephone, records it (passive tracking), and issues directions based on it (computer directed). It really does not matter if the information comes directly from the handling machinery, the operator of the handling machine, or a CRT operator in radio contact with the machine operator; as long as the information is accurate and timely. Since all that is needed for a computer directed operation is accurate and timely information, not automation, even the small marine terminal can realize all of the benefits of computer directed management.

In general, the management areas of a marine terminal operation currently susceptible to computer direction are performed by low level management and clerical personnel. The computer cannot outperform a creative person, but for jobs that have simple decision rules and require dogged uninterrupted concentration; the computer can outperform a person. The management roles that will be reviewed here are:

• Spot selection
• Pooling
• Short moves

All computer direction attempts to achieve the same level of performance as a conscientious supervisor performing the same task.

Spot Selection

When a truck arrives at the ingate, a spot must be selected in the terminal for the container. If the facility has only one gate lane, then a person responsible for planning can give the ingate clerk the list of available spots in the yard. If there is more than one gate lane and a clerk assigning spots at each lane, then the spot selection list must be split. In a congested terminal, this is difficult to do. Instead of distributing the list to the gate clerks, the yard planner can give the list to the computer. The computer will select the spot from the list when the clerk at each gate lane notifies the computer that a truck has arrived. This same concept can be extended to the delivery of empty containers to a truck.

Short moves

When a yard handling equipment operator reaches a bottleneck, it is not unusual for the operator to wait until the bottleneck has cleared before continuing work. For instance, if the quay crane is moving hatch covers, all of the equipment assigned to the quay crane will soon be idled. A computer directed Level-3 terminal control system would have the vessel work list and recognize this condition. Until this condition had cleared, the Level-3 computer would alter the work list which moved containers from the yard directly to the vessel. The handling equipment would be instructed to deck the containers at available spots short of the quay crane, allowing the landside handling equipment to continue on the work list. When the hatch covers had been moved, the prestaged containers would be moved to the quay crane for a burst of high productivity.

This same concept extends to the discharge operation where the quay crane is generally much faster than the landside handling equipment during an on-deck discharge, and much slower during a below deck discharge. When the landside handling equipment starts to lag the quay crane, the Level-3 computer system will reassign containers to intermediate deck positions near the quay crane. The productivity of the landside handling equipment is now matched to the quay crane and the containers are placed by the Level-3 computer into a rehandle work list. The rehandle work list will move the containers to their proper location one by one any time the yard handling equipment has an idle moment.

Pooling

Usually a terminal operator will assign handling equipment as a pool. There is a pool of handling equipment for the gate operation and there is a pool of equipment assigned to each quay crane operating against a vessel. Some of the pools will be under-utilized, relatively idle, and some will be over-utilized, a bottleneck in the operation. These pools are based on historic terminal management techniques. There is a clerk in charge directing each of the pools. The maximum size of the pool is restricted to the number of pieces of equipment that can be managed by the clerk in charge. In addition, equipment cannot be moved quickly from one pool to another and back without confusing the management of the pools. From the Level-3 standpoint, there is a list of work to be done and a list of equipment to do it. Each work instruction in the work list has an appropriate priority. The entire terminal can be considered one pool of equipment. As each piece of handling equipment completes a move, it is assigned another container move based on many factors including: its position in the facility and the priority of moves to be accomplished. The weight of the factors in selecting the next move can be adjusted by terminal management.

Which computer system?

In the last 20 years the relative economics of computer systems have come full circle. The basic economic trends in the computer industry are that computer software costs are increasing and that computer hardware costs are decreasing. From the 1950s to the 1970s, computer hardware was very expensive relative to computer software. These simple computer programs were relatively inexpensive and routinely were completely rewritten. That equation has changed today:

• Computer hardware prices have dropped dramatically.
• The labor cost of a computer programmer has increased equally dramatically because of the demand for capable programmers.
• Computer programs written today are a more significant economic investment than the computer hardware, the software is no longer expendable. In the 1980's the computer hardware is the throw away investment.

The computer system selected should have the flexibility to allow the marine terminal to start with a passive tracking operation and move to a computer directed operation. In the computer directed operation, the terminal will have turned some clerical and low level management capability over to the computer. The computer directed operation will be adjusted over time with management's experience and the terminal's preferred operating procedures. In this environment, the computer system should be flexible and structured in uch a way that it will survive to maintain this long term management investment. To consider the structure required, computer systems are usually divided into two areas:

1. Hardware: the actual machinery used to run the computer program.
2. Software: the collection of computer programs running on the computer.