Multi-objective seaport planning by MOORA decision making

Abstract

An approach is needed to localize in an optimal way a seaport facing different indicators, criteria or objectives sometimes from different groups or individuals. The internal mechanical solution of a Ratio System, producing dimensionless numbers, is preferred to Cost-Benefit or to Weights which most of the time are used to equalize the different units. The ratio system creates the opportunity to use a second approach: a non-subjective Reference Point Theory based on the found ratios. The two approaches form a control on each other. This theory is called MOORA (Multi-Objective Optimization by Ratio Analysis). As an application a ranking is made for the best location of a new seaport or for the expansion of an existing one given a set of objectives to be fulfilled.

Appendices

Appendix A: The ameliorated nominal group technique

The ameliorated approach of the nominal group technique, which is explained here, was ameliorated by Brauers (1987, 2004a, 2004b, 2004c, 44–64), but the Nominal Group Technique was first elaborated by Van de Ven and Delbecq (1971).

1.1 A.1 The original nominal group technique

The nominal group technique consists of a sequence of steps, each of which has been designed to achieve a specific purpose.

• 1. The steering group or the panel leader carefully phrases as a question the problem to be researched. Much of the success of the technique hinges around a well-phrased question. Otherwise the exercise can easily yield a collection of truisms and obvious statements. A successful question is quite specific and refers to real problems. The question has to have a singular meaning and a quantitative form as much as possible.

• 2. The steering group or the panel leader explains the technique to the audience. This group of participants is asked to generate and write down ideas about the problem under examination. These ideas too have to have a singular meaning and a quantitative form as much as possible. Participants do not discuss their ideas with each other at this stage. This stage lasts between five and twenty minutes.

• 3. Each person in round-robin fashion produces one idea from his own list and eventually gives further details. Other rounds are organized until all ideas are recorded.

• 4. The steering group or the panel leader will discuss with the participants the overlapping of the ideas and the final wording of the ideas.

• 5. The nominal voting consists of the selection of priorities, rating by each participant separately, while the outcome is the totality of the individual votes. A usual procedure consists of the choice by each participant of the n best ideas from his point of view, with the best idea receiving n points and the lowest one point. All the points of the group are added up. A ranking is the democratic result for the whole group.

The Original Nominal Group Technique can be characterized as weak robust as the participants expressed too much their personal feeling. For that reason amelioration was proposed.

1.2 A.2 The ameliorated nominal group technique

As there was too much wishful thinking even between experts better results were obtained if the group was also questioned about the probability of occurrence of the event, here an objective. In this way the experts became more critical even about their own ideas. The probability of the group is found as the median of the individual probabilities.

Finally, the group rating (R) is multiplied with the group probability (P) in order to obtain the effectiveness rate of the event, (E):

$$E = R \times P $$

The effectiveness rates of the group are ordered by ranking.

In an example of application of the Nominal Group Technique for the Facilities Sector in Lithuania the group of stakeholders was composed of 15 stakeholders (see Brauers and Lepkova 2003). A neutral panel leader directed the exercise. Each participant has chosen the most important five objectives from his point of view, with the most important objective receiving five points and the less important one point. The introduction of probabilities of realization, introducing a sense of reality and presenting a guaranty against wishful thinking, produces quite some changes in the ranking.

The total 225 is a control figure for the group result. Indeed, each participant could distribute maximum: 5+4+3+2+1=15 points. With 15 participants, the total has to be not more than 225. It could be less, as each participant is not obliged to allot 15 points. The total of the given points, here namely 225, means that each participant used his rights completely. The reality check, however, diminished the figure to 145.21.

Contrary to Delphi, convergence is not aimed at, but final voting is used. In this way, Nominal Group Technique could be considered as exploring any idea about objectives, advisable for a preliminary version of Delphi, where convergence could be reached about the list of objectives. Delphi is treated in next appendix.

Appendix B: The Delphi method

The Delphi method is a method for obtaining and processing judgmental data. It consists of a sequenced program of interrogation (in session or by mail) interspersed with feedback of persons interested in the issue, while everything is conducted through a steering group.

We advocate the most this method as it also takes care of:

• quantitative treatment

• expert knowledge

• anonymity

• convergence.

Dalkey and Helmer (1963) used Delphi in its present form for the first time around 1953. The essential features of Delphi are:

• 1. A group of especially knowledgeable individuals (experts)

• 2. Inputs with a singular meaning and quantitative as much as possible

• 3. The opinions about the inputs are evaluated with statistical indexes

• 4. Feedback of the statistical indexes with request for re-estimation also after consideration of reasons for extreme positions

• 5. The sources of each input are treated anonymously

• 6. Two developments: meeting and questionnaires. The organization of a meeting produces quicker results. However, the meeting has to be organized in such a way that communication between the panel members is impossible Therefore, a central computer with desk terminals, television screen and computer controlled feedback is advisable.

As an example of Delphi with as experts medical doctors, chemists, and representatives from the pharmaceutical sector the following question is asked: will an effective cure for AIDS be found after: 10, 20, 25, 50, 75 years or never?

Suppose the median reports: the cure will be found after 25 years with as first quartile: 20 years and as third quartile: 50 years. Skewness is still too large; a new round may help. A second round is foreseen, then a third round, a fourth round etc. until convergence is reached as much as possible. During the exercise reasons for extreme positions, which could have been unnoticed by the participants, are reported too.

Convergence in opinion between all stakeholders to give more importance to an objective results from a Delphi exercise, which could provide the given objective with a Significance Coefficient. For instance, giving a significance coefficient to pollution abatement, the stakeholders are asked to give the following importance to pollution abatement:

$$0, 1, 2\ \mbox{or}\ 3 $$

Suppose for instance that after several rounds convergence is reached on 3.

As an illustration, an application of Delphi for an International Music Competition Jury is discussed elsewhere (Brauers 2008a, 170–173).