Olivia Smith Angus Amy

Lewis Hopkins, the author of this selection, is the Professor of Urban and Regional Planning emeritus. In addition to his work on the idea of the plan, he has researched computerised decision support systems in planning. He has edited numerous texts and is a member of Urbana Plan Commission.

A plan can work in one or several of the following ways:  Agenda  Policy  Vision  Design  Strategy

Is a tool that focuses the attention of a constituency, put simply a list of things to do. It effects the way decisions will be made on important actions or issues. Publicly advocating an agenda serves as a memory device and a commitment to the community.

A policy works by automating repeat decisions to save time or by ensuring that the same action is taken in the same circumstances, which yields fairness or predictability. It works in three ways: saving decision costs, ensuring consistency and fairness and increasing predictability.

A vision is an image of what should be and is used to compel actions. A vision interpreted as a normative forecast: a desired future that can work if people can be persuaded that it can and will come true. Visions are useful in situations in which they can change beliefs and thereby change investment actions, regulations, or activity patterns of residents.

A design is fully worked outcome. Designs work by determining a fully worked outcome form interdependent actions and providing this outcome as information before any action is taken. Designs fit situations in which there are highly interdependent actions, actions are easily inferred from information about the outcome and there is little uncertainty about the implementation of actions.

Strategies work by determining what action should be taken now contingent on related future actions. Strategies fit situations where there are many interdependent actions under the authority of many actors and occurring over a long time in relation to an uncertain environment. Explicit about relationships among interdependent actions, consequences, intentions, uncertainties and outcomes.

Investments in physical infrastructure or facilities and regulations are widely recognised as the two major components of urban development plans. As in political interpretations, these different types of actions imply different tasks for plans.

Regulations change rights and the range of discretion in making decisions. Regulations have two kinds of decisions; decisions to regulate and decisions to act given regulations. The decision to regulate is usually collective whilst the decision to act is individual. These decisions must be pre-emptive as there is no use in regulating once investment is underway.

Investments change capital stock in infrastructure and mediate between geographic space and peoples behaviours. Thus two kinds of decisions matter: the decision to invest in infrastructure and the decision to use the resulting infrastructure in particular ways. The important point is that investments occur in fixed locations and they create the physical context within which locational choice and daily behaviours occur.

In relation to the explanation of how plans work there are a number of points that we should expect to observe:  Plan-making behaviours  Plans  People using plans while making decisions  Investments and regulations that may have been affected by plans, and  Outcomes in terms of activity patterns resulting from these investments and regulations

These observations provide opportunity for assessment. There are four broad criteria for assessing whether a plan works:  Effect  Net benefit  Internal validity  External validity

Did the plan have any effect on decision making, actions, or outcome? For example, if it was intended to work as an agenda, how many of the listed actions were taken?

Was the plan worth making and to whom? For example, if it was intended to work as strategy were the gains over time sufficient to compensate the costs of making the plan?

Internal - Did the plan fulfil the logic of how it was intended to work? External – Did the outcomes intended or implied in the plan meet external criteria such a plans for a just society? Ethical acceptability is a crucial component of external validity.

Plans can work in more than one way. Given explanations of how plans work it is possible to assess to what extent plans work in particular situations with respect to their effects, net benefit, internal validity and external validity. These can also be used to predict what plans will meet evaluation criteria and which plans will be worth making.