which each alternative plan is acceptable to, or conforms to the preferences of, those
policy makers who have the power of decision is a measure of the plan’s political
feasibility. Clearly, the policy makers themselves should be involved in this ranking
process. The aim behind the presentation of the quantitative methods discussed in
this chapter is to help economists, engineers, and planners in an effective participation during a responsible political decision-making process.
14.1.2 Infrastructure Planning
The outcome of any public policy is uncertain because of
(1) factors beyond the control of the planner or decision maker,
(2) a limited ability to simultaneously take into account all relevant data pertaining
to the policy even without uncertainty.
(3) the limited capacity of an individual planner or group of planners even when
assisted by computers.
This uncertainty complicates the formulation and selection of alternatives.
14.1.3 The Role of Modelling
When multi-objective planning problems become complex, planners try to build
simplified representations of their complex problems, so that whatever information is
available may be processed more efficiently so as to forecast and assess the possible
outcomes. These simplified models or representations can be conceptual (within the
mind of the planner or decision maker), or be more complicated, better defined by
many and various algebraic equations (within a flow chart diagram), to be solved by
a computer programme. These are called mathematical models.
Mathematical models can provide a useful means of bringing the diverse elements of the planning process together in a conceptual framework that ideally
facilitates better understanding of alternatives by both the planner and the decision
maker.
Most mathematical models produce quantitative results: figures which lead to
certain decisions. Nevertheless, the information these figures give may significantly
help the decision-making process during the selection of a best alternative. In the
case where multiple objectives are being evaluated, there are, very often, some
alternatives which are preferable with respect to certain objectives, and conversely,
other alternatives being preferred when different objectives under scrutiny. The
problem becomes more complex as the number of pertinent objectives and possible
alternatives increases, resulting in a decreasing ability of the planner to understand
and solve the problem. At this stage, experts in quantitative modelling techniques
can be of immense value, not to replace the responsible political decision-making
process, but only as helpers.
384
14 Multi Sector/Purpose Infrastructure Planning
policy makers who have the power of decision is a measure of the plan’s political
feasibility. Clearly, the policy makers themselves should be involved in this ranking
process. The aim behind the presentation of the quantitative methods discussed in
this chapter is to help economists, engineers, and planners in an effective participation during a responsible political decision-making process.
14.1.2 Infrastructure Planning
The outcome of any public policy is uncertain because of
(1) factors beyond the control of the planner or decision maker,
(2) a limited ability to simultaneously take into account all relevant data pertaining
to the policy even without uncertainty.
(3) the limited capacity of an individual planner or group of planners even when
assisted by computers.
This uncertainty complicates the formulation and selection of alternatives.
14.1.3 The Role of Modelling
When multi-objective planning problems become complex, planners try to build
simplified representations of their complex problems, so that whatever information is
available may be processed more efficiently so as to forecast and assess the possible
outcomes. These simplified models or representations can be conceptual (within the
mind of the planner or decision maker), or be more complicated, better defined by
many and various algebraic equations (within a flow chart diagram), to be solved by
a computer programme. These are called mathematical models.
Mathematical models can provide a useful means of bringing the diverse elements of the planning process together in a conceptual framework that ideally
facilitates better understanding of alternatives by both the planner and the decision
maker.
Most mathematical models produce quantitative results: figures which lead to
certain decisions. Nevertheless, the information these figures give may significantly
help the decision-making process during the selection of a best alternative. In the
case where multiple objectives are being evaluated, there are, very often, some
alternatives which are preferable with respect to certain objectives, and conversely,
other alternatives being preferred when different objectives under scrutiny. The
problem becomes more complex as the number of pertinent objectives and possible
alternatives increases, resulting in a decreasing ability of the planner to understand
and solve the problem. At this stage, experts in quantitative modelling techniques
can be of immense value, not to replace the responsible political decision-making
process, but only as helpers.
384
14 Multi Sector/Purpose Infrastructure Planning