maker, the optimal plan is the one on the boundary curve that attains the highest
iso-preference curve, e.g., plan C in Fig. 14.3.
The remaining sections will discuss modelling techniques that have been proposed for identifying efficient trade-offs as indicated by plans on an objective
transformation surface (for n-dimensional planning problems) and for estimating
optimal trade-offs or plans, i.e., those that attempt to maximize political preferences.
Since data generally do not exist to define completely either transformation or
isopreference surfaces, the modelling techniques will attempt to approximate the
surfaces by considering a relatively small number of efficient planning alternatives.
Conceptually, the approaches correspond to the procedure illustrated in Fig. 14.3.
However, in practice, the complete mapping of feasible and efficient alternatives is
seldom possible or even necessary.
When defining the possible trade-offs among several objectives, whatever
method is used will probably yield many efficient alternative solutions. When the
number of objectives grows, there is a corresponding increase in number of alternative available solutions defining the possible trade-offs among these goals. This
results in increased computer time being required and is more expensive. Another
consequence is the decision maker needing more time to understand and assess the
numerous solution vectors defining the efficient trade-offs. Unfortunately, decision
makers rarely have the time to do this.
Decision makers do like the authority or power to take decisions, but are quite
reluctant to sift through a large number of alternative (efficient) solutions to a
particular problem, and use their judgement to select the best alternative. Instead
they would request their own staff or an appropriate agency to give their opinion of
the one, apparently best, solution, and then either decide to accept or to reject it. This
request can viewed in two ways: (1) the burden of trading off the values of
conflicting objectives gets shifted to the technicians proposing the single policy
solution, and who do not best represent the needs of society. If the decision makers
consider as good the trade-offs the technicians have made, their proposed policy will
be accepted, However, very often, the technicians will focus on what they believe the
decision maker would prefer, without this being necessarily an optimal solution;
(2) as an opportunity by the planners to push forward what they consider an optimal
solution, in terms of the parameters studied. It has been seen in Chap. 8, that
politicians have their own perception about projects and plans to which they give
more weightage. A feasibility report (100–500 pages) usually contains a summary,
called the executive summary (5–20 pages to be read by executives!). When the
feasibility report (see also Chap. 22) is sent to the client, by the consulting agency,
the technicians are expected to go through the report, and prepare a summary for the
official directly reporting to the politician. It can be imagined that if the executive
summary is already available, the technicians will not lose much time in preparing a
summary. Knowing that the politician never likes to have more than a one-page
report to guide him, the agency (with the relevant guidance from the client’s
technicians) can also prepare this summary with the proper recommendations for
the politician. This is how some bright planners can get the decision maker to take
decisions for the benefit of the country, rather than for some other reason. How do
394
14 Multi Sector/Purpose Infrastructure Planning
iso-preference curve, e.g., plan C in Fig. 14.3.
The remaining sections will discuss modelling techniques that have been proposed for identifying efficient trade-offs as indicated by plans on an objective
transformation surface (for n-dimensional planning problems) and for estimating
optimal trade-offs or plans, i.e., those that attempt to maximize political preferences.
Since data generally do not exist to define completely either transformation or
isopreference surfaces, the modelling techniques will attempt to approximate the
surfaces by considering a relatively small number of efficient planning alternatives.
Conceptually, the approaches correspond to the procedure illustrated in Fig. 14.3.
However, in practice, the complete mapping of feasible and efficient alternatives is
seldom possible or even necessary.
When defining the possible trade-offs among several objectives, whatever
method is used will probably yield many efficient alternative solutions. When the
number of objectives grows, there is a corresponding increase in number of alternative available solutions defining the possible trade-offs among these goals. This
results in increased computer time being required and is more expensive. Another
consequence is the decision maker needing more time to understand and assess the
numerous solution vectors defining the efficient trade-offs. Unfortunately, decision
makers rarely have the time to do this.
Decision makers do like the authority or power to take decisions, but are quite
reluctant to sift through a large number of alternative (efficient) solutions to a
particular problem, and use their judgement to select the best alternative. Instead
they would request their own staff or an appropriate agency to give their opinion of
the one, apparently best, solution, and then either decide to accept or to reject it. This
request can viewed in two ways: (1) the burden of trading off the values of
conflicting objectives gets shifted to the technicians proposing the single policy
solution, and who do not best represent the needs of society. If the decision makers
consider as good the trade-offs the technicians have made, their proposed policy will
be accepted, However, very often, the technicians will focus on what they believe the
decision maker would prefer, without this being necessarily an optimal solution;
(2) as an opportunity by the planners to push forward what they consider an optimal
solution, in terms of the parameters studied. It has been seen in Chap. 8, that
politicians have their own perception about projects and plans to which they give
more weightage. A feasibility report (100–500 pages) usually contains a summary,
called the executive summary (5–20 pages to be read by executives!). When the
feasibility report (see also Chap. 22) is sent to the client, by the consulting agency,
the technicians are expected to go through the report, and prepare a summary for the
official directly reporting to the politician. It can be imagined that if the executive
summary is already available, the technicians will not lose much time in preparing a
summary. Knowing that the politician never likes to have more than a one-page
report to guide him, the agency (with the relevant guidance from the client’s
technicians) can also prepare this summary with the proper recommendations for
the politician. This is how some bright planners can get the decision maker to take
decisions for the benefit of the country, rather than for some other reason. How do
394
14 Multi Sector/Purpose Infrastructure Planning