On the concept of sustainability – assessing the sustainability of large public infrastructure investment projects

Abstract

Assessing the sustainability of large public investment projects within the general framework of three-pillar thinking is a complex affair. Such ventures involve multiple actors – e.g. planners from various disciplines such as engineers, economists and social scientists, in addition to politicians, users and other people affected – each carrying with them particular agendas and priorities, and corresponding understandings of the concept of sustainability. In this paper, we propose to frame the concept of sustainability assessment within the context of investment projects, in order to enable communication between the multiple actors, to assess different impacts of an investment project against one another in a meaningful way and, ultimately, to enhance the commensurability of investment project alternatives. Our main idea is that there exist different levels according to which the assessment of sustainability ought to refer – operational, tactical and strategic – and that properly addressing these levels can permit the different actors to comprehend one another, and thereby allow for more clarity and positive action.

Keywords::

• sustainable business models
• sustainability
• life-cycle assessment

Keywords::

• framework
• strategic
• benefit
• long-term
• risk

1. Introduction

The concept of sustainability (and the adjacent one of sustainable development) is multifaceted, and is used in different manners within different contexts. As Gomis et al. (2011, 174) pointed out, ‘sustainable business’, ‘sustainable technology’, ‘sustainable agriculture’, ‘sustainable economics’, etc. are all buzzwords of the literature today. According to Adams, ‘[a]nalysts agree that one reason for the widespread acceptance of the idea of sustainable development is precisely [its] looseness. It can be used to cover very divergent ideas […]. The concept is holistic, attractive, elastic but imprecise’ (2006, 3). This differentiated use has in fact, according to Marshall and Toffel, ‘nearly rendered the term sustainability meaningless’ (2005, 673).

The ambition of this paper is precisely to carve out a more firm understanding of how to assess sustainability within the context of large public investment projects.4 In doing this, we follow the OECD (1991, 5) that has introduced the concept of sustainability into the domain of project management. According to their model, sustainability is, together with efficiency, effectiveness, impact and relevance, a criterion according to which investment projects are to be assessed. This use of the concept of project sustainability is then to be understood as more restraint than the considerable wider concept of ‘sustainable development’ as first defined in the Brundtland report of 1987.5

The precision of which context we address is in fact crucial for understanding the point we are trying to make. Engineers, planners from other disciplines, and politicians, union representatives and environmentalists tend to understand the concept of public project sustainability in widely different manners and from different perspectives. Some use the concept of sustainability in order to describe asphalt qualities (NAPA 2009), while others insist that road construction for personal vehicle use is not sustainable at all. Clearly, an emerging comprehension of the role of engineers is that engineers have a major responsibility for, and role in, the development of sustainable solutions (Rahimifard and Clegg 2008). If the stakeholders do not know the context of the discourse on sustainability, confusion and misapprehension will prevail between them.

In this paper, we therefore propose to sort the semantic landscape in order to permit these different actors to comprehend one another, and thereby allow for more clarity and positive action. In fact, our analysis comes as a response to a pressing problem. First, it is not clear what one is to assess when one is asked to assess the sustainability of an investment project, and, second, it seems equally unclear as to how it should best be assessed. Several research traditions assess sustainability, but there seems to exist confusion concerning how to understand the concept itself. Something more tangible and robust is needed. In our opinion, both the difficulty of determining what principles constitute the essence of the concept and the problem of putting into practice the principles agreed upon stem from inherent characteristics of the concept itself, and provoke the need for analysis thereof.

2. Ambition of this paper and methodological restraints

We examined how sustainability is addressed in ex ante evaluations of large investment projects. To do this, we carried out extensive literature search, analysed ex ante evaluation reports from 24 investment projects having undergone scrutiny in the Norwegian Quality Assurance (QA) regime and interviewed 14 planners. Our respondents are employed in public agencies with responsibility for project execution, in ministries with responsibility for future users and in external QA consultancies. The results from these research projects inspired us to conduct this study.

With the concept of sustainability being elusive, methodological approaches intended to assess sustainability are multiform and manifold. We do not have the ambition to explain all such approaches in this paper, but solely outline the ones that we found to be most pertinent for assessing the sustainability of large public investment projects. The ambition of this paper can be resumed in the following three points:

• We illustrate how the understanding of sustainability and the corresponding understanding of sustainability within the context of investment projects ought to be sorted according to separate analytic levels.

• Equally, we illustrate how the identification of these analytic levels deepens the idea of three-pillar thinking.

• Finally, we analyse how already existing analytic tools can serve to assess the sustainability of large public investment projects if properly understood.

Our aim is therefore not to present any fixed, ready-made procedure for sustainability assessment within the context of investment projects; rather, we wish to clarify what one is to assess when assessing the sustainability of such projects, and how existing methodological approaches can contribute to such assessments. Sustainability assessment is complex, but a clarification of what to look for when assessing the sustainability of large investment projects ought to contribute to a more firm understanding.

3. Etymology and definitions of sustainability in a project context

Generally speaking, what we judge to be sustainable denotes the upholding of what we judge advantageous over a long time.6 For instance, the kingdoms of France and Britain upheld almost continually a state of war for over 100 years in the high middle ages; hardly anyone would call such a venture sustainable, especially considering the tremendous social and economic impacts of the strife. The concept of sustainability therefore needs to be understood as a prescriptive rather than a purely descriptive concept.

Aiming at surpassing the limits imposed by pure etymology, a common point of departure when discussing the concept of sustainability within the context of large public investment projects is the definition provided by the OECD (2002, 36).7 According to OECD, the sustainability of development projects is to be understood as:

The continuation of benefits from a development intervention after major development assistance has been completed. The probability of continued long-term benefits. The resilience to risk of the net benefits flows over time.

This definition enlists, in our opinion, the key elements pertaining to the assessment of sustainability also outside the development context. Such a definition is, however, by no means self-explanatory and invites comments.

Four essential components of sustainability can be found in the definition. First, we can see the emphasise on the need to secure long-term benefits, i.e. the project fulfils its aim over the intended time frame. Second, the concept of net benefits refers to the idea that wider (negative) impacts may overshadow the intended (positive) effects of the project or vice versa. However, it is by no means clear as to how to balance different impacts against each other. The willingness-to-pay principle is one alternative (as in Cost–Benefit Analysis), but it is not politically neutral and not always considered acceptable. Third, the emphasis on resilience to risk highlights the need for robustness and predictability of the effects that the project is intended to fulfil. We consider that the literature amply covers the first three elements of the definition described in this manner, without in any way underestimating the complexity involved in accomplishing them.

Fourth, the insight that projects are built for a reason, i.e. the sustainability depends on the achievement of benefits, is not entirely unambiguous, in that it is not always quite clear exactly what benefits the investment project is intended to obtain. Consequently, in order to judge whether an investment project can be considered sustainable ex ante, we need to decide what requirements and corresponding benefits it is intended to fulfil.8

Passing from the acknowledgement of the key elements in the above definition, however, only takes us so far in our quest for the assessment of sustainability. In order to assess the sustainability of investment projects ex ante, methodological tools that can provide us with concrete analytic elements according to which the project can be evaluated are needed. As exposed in the following paragraphs, several such tools exist. Acknowledging in what they differ is a key element to understanding in what manner sustainability can be assessed within the context of investment projects.

3.1 The term ‘sustainability’ – levels of analysis

An investment project is most often realised through a project with given objectives (time, cost and quality). Railways, opera houses, roads, Information and Communications Technology (ICT) systems, etc. are thus constructed according to given requirements of time, cost and quality. However, the project is normally realised as part of a general process intended to achieve certain goals for a certain target group. This is the first understanding of the benefit from the definition. In other words, it is important to realise that an investment project is carried out in a particular context. A railway project is constructed in order to transport commuters from A to B. This transport process is part of a more general societal process, with purposes as transport efficiency and economic development. They can be considered as higher-order benefits. To illustrate this point, we can consider the relationship between the project, the process and the societal process, as shown in Figure 1.

Figure 1 Three sequential planning perspectives in a project based on cause–effect relationships. Step 1: assets are provided to enable project operations to produce contract deliverables. Step 2: the project's deliverables contribute to the fulfilment of the project's first-order (tactical) effects by satisfying the prioritised requirements based on selected prioritised needs of selected target groups. Step 3: fulfilment of the project's first-order (tactical) objectives contributes to the fulfilment of the project's second-order (strategic) effects based on policy response to the priorities of the larger society.

The deliverables and the effects of investment projects can thus be linked to different perspectives. The perspective can be operational (project outputs), tactical (goals) or strategic (purposes). In our viewpoint, the same logic may be applied to the assessment of sustainability within the context of investment projects. When carrying out the assessment, we maintain that all effects pertaining to sustainability should refer to the corresponding perspectives they belong to. Similarly, sustainability of an investment project should therefore refer to the same, but since the final success of a project depends on the perspective under consideration, a reference to the perspective is required. The reason for this is that a project can be deemed sustainable when considered in one perspective and not necessarily in another. A complete sustainability assessment of an investment project should consequently address all three levels before drawing the final conclusion.

When laying out “sustainable asphalt”, the specific goals can be constructing and maintaining a road in an environmentally friendly way, for instance by reducing pollution and even noise during the construction phase. This may render the project sustainable in the operational perspective, but not necessarily in the tactical and the strategic ones, where the latter refer to sustainable processes based on political deliberations, such as creating the framework conditions for level-headed economic development. Consequently, the first of these concerns – the choice of asphalt solution – can be deemed sustainable (or not) at an operational level. The second concern – the choice of constructing a road in order that people in a region can communicate more easily – can be regarded to be sustainable (or not) at a tactical level. The third one – the ambition to create framework conditions for improved economic growth – can be considered to be sustainable (or not) at a strategic level.9

Our point is that although it makes, in fact, perfect sense to characterise different effects at all levels as sustainable or not, it is essential to avoid confusing these levels when assessing sustainability within the context of an investment project or when choosing between different project alternatives. In fact, what can be described as sustainable at one level may not be sustainable at the next level. In other words, we need to acknowledge the difference between doing the projects more sustainable and choosing the more sustainable projects.

The number of elements that may be addressed in order to establish whether or not an investment project can be judged to be sustainable can reach significant numbers (Norman and MacDonald 2004, 252). Without comprehending to what level of analysis these elements pertain to, the risk of confusion impends.

In our opinion, then, the main problem is not, as suggested by Marshall and Toffel (2005), that the concept of sustainability has become too broad, in that it includes too many views and opinions about desirable objectives and recognised inconveniences. Rather, we maintain that the problem in understanding the multitude of these elements is caused by a lack of sorting them according to whether they concern an operational level, a tactical level or a strategic level.

But what then to analyse when assessing the sustainability of large public investment projects? In our viewpoint, the answer to this must be based on the understanding of sustainability as conceptualised within the perspective of three-pillar thinking.

3.2 Balancing the three pillars of sustainability

Despite the apparent imprecision concerning the comprehension of the notion, a certain general agreement does nonetheless seem to exist. As Adams pointed out, the ‘core of mainstream sustainability thinking has become the idea of three dimensions, environmental, social and economic sustainability’ (2006, 2). Sustainability can be analysed with different aspects in mind, but the three dimensions can be used to categorise the identified sustainability factors or elements (Flores et al. 2008). When we in the following lines use the term ‘sustainability’, we therefore acknowledge these three dimensions, and there exists a need for a balance between the three.10 A public infrastructure investment project will normally have both positive and negative impacts. For example, when political decision-makers decide to start up a project with positive economic and negative environmental impacts, they have made a trade-off between these two kinds of impact.

Most large investment projects will comporte impacts for the surrounding society, and some of these impacts will prove to be of a longer-lasting nature than others. This applies for impacts within all the three sectors. The main argument underlying sustainability assessment is that the project's predictable impact on none of the systems ought to be disregarded, either the economic, social or environmental system surrounding the investment project.

In the development sector, wherefrom the origin of investment project sustainability assessment is commonly referred to, economic development and social development are often the main ambitions of the project. If the project is to be given a go ahead, environmental sustainability needs also to be assured (OECD 1991). If the decision to invest is taken with a very narrow focus, for instance on the economic impacts of the investment only, significant social and environmental problems can accompany the investment project and may render the project negative to the society as a whole. Such a project must accordingly be assessed as not sustainable.

Within the context of public investment projects, this insight proves to be particularly crucial, since the general goal of the public sector is not to generate profit but to assure the present and future well-being of the citizens.

3.3 Assessing economic sustainability

An assessment of economic sustainability concerns mainly the profitability of the invested capital, cost efficiency, financing over time and flexibility.

From a corporate perspective, the profitability of the invested capital can be measured by comparing costs and income of the investment over its (intended) lifespan, in order to judge whether or not the profitability is (1) positive and (2) higher than that for alternative investments.

From the perspective of a public investment project, the measure of economic sustainability alters. Public investment projects – such as infrastructure projects or defence equipment procurements – are often characterised by being public benefits, and organising payment by use is often neither possible nor desirable. Therefore, financing such an investment project often needs organising forced financing via taxes.

Cost efficiency concerns to a large degree the choice of factor inputs and technology, in addition to project governance and management. A central concept permitting for comparison is that of life-cycle analysis, since projects are characterised by differentiated cost/benefit structures over time. Such an analysis permits displacing of focus from solely investment costs to future maintenance and operational costs.

The Asian Development Bank (1997) outlined three concerns that ought to characterise assessments of public sector investment projects:

• financing from public budgets,

• possibility for financial contributions from user groups,

• long-term incentives for interested parties to keep up/continue the investment project.

In our opinion, adjacent factors such as the availability of manpower and other resources over an extended timeline need equal consideration. Otherwise, the operational phase of the investment project may be exposed to altered framework conditions, often resulting in increased demand for resources.

Lastly, flexibility needs consideration on the subject of economic sustainability. If the need for the investment project changes, then the economic sustainability will depend on the capacity to alter it or the cost of terminating it.

3.4 Assessing environmental sustainability

Environmental impacts can be categorised in several ways, for instance as irreversible or reversible. The first category refers to such impacts that cannot be reversed even if one tries to do so, for example the use of critical resources, extermination of species, irrevocable climate changes, etc., whereas the latter can be reversed. The differentiation between such impacts is rarely absolute, but will often depend on the temporal frame chosen in the assessment. Nature's healing capacity for emissions and other pollution is remarkable, but there are limitations to this ability. It is generally accepted that in case of doubt, a principle of caution needs to be applied (as emphasised in the so-called Rio Convention of 1992).

Another categorisation of environmental impacts is based on geography. Environmental problems can be local, regional, national and global. One common reason that such impacts are not addressed in a sufficient manner is the lack of private ownership. Coping with such problems therefore needs public intervention, via prohibitions or prescriptions, taxes, quotas, etc. The global nature of some environmental impacts (for instance, greenhouse gas emissions) necessitates global corporation, rendering the determination of effective measures complex.

A third type of categorisation concerns the usability for humans. Economic literature distinguishes between phenomena with and without the use value. Such a use value can denote consumption of biological produce (e.g. foodstuff, construction materials, pharmaceuticals), recreational use or more basically healthy surroundings. Phenomena without the use value, such as outlined here, will then include nature's intrinsic value and the transmittance of this to future generations.

3.5 Assessing social sustainability

Social sustainability is generally considered as the most problematic of the sustainability assessment fields. As McKenzie commented, ‘[s]ocial sustainability is far more difficult to quantify than economic growth or environmental impact and consequently it is the most neglected element of triple bottom line reporting’ (2004, 7).11 This general remark implies that there are similar challenges within the context of sustainability assessment of investment projects.

Generally speaking, a socially sustainable investment project will contribute to what is considered as positive societal development, concerning both the society as a whole and the well-being of its citizens. In most societies, covering basal needs such as clothing, food, safety, justice and health will be considered as positive contributions. Equally, most abstract goods, such as gender equality, democratic rights and individuals' self-realisation, will often be considered to be of this nature.

Questions of equality and equal distribution of goods and disadvantages are of particular interest within this context. Dimensions of equality will typically be:

• income,

• health,

• working conditions,

• geographical distribution,

• generational concerns,

• minority group concerns,

• gender concerns.

Such concerns should be brought to the forefront of project assessment. It is equally notable that the distinction between universal values and interest-group concerns is not fixed in any manner. More generally speaking, there rarely exists any perfect consensus for the use of society's resources, a fact that renders the assessment of social sustainability problematic.

Such general considerations concerning the pillars of sustainability are not, however, sufficient to fully understand the assessment of sustainability within the context of an investment project. In order to arrive at a reasonable understanding, the general understanding of three-pillar thinking needs to be coupled with a clear comprehension of what exactly large investment projects are expected to fulfil.

3.6 Assessment of sustainability – some analytic tools

Not surprisingly, since sustainability denotes a complex phenomenon, the methodological approaches utilised for assessment vary. Table 1 lists some of the common tools for the assessment of sustainability. The fact that there exist many such tools illustrates a general point. The different comprehensions of the term ‘sustainability’ correspond to a plethora of tools. The tools tend to vary with respect to what level of analysis (operational, tactical or strategic level) they base their analysis on and whether they include assessments of elements within one, two or all three pillars. If they include all three pillars, there is also a variation with respect to whether and how different impacts are balanced. In fact, what these tools assess tend to reflect the concept of sustainability that permeates the evaluator. Here, we indicate that all these methodologies assess the criterion that it is useful to assess; however, without a proper understanding of what they are assessing, one in relation to another, some confusion seems to result.

Table 1 Short descriptions of some selected methods that are commonly used to assess the sustainability of projects.

Analytic tool	Short description of some analytic tools commonly used for a separate assessment of one of the three pillars of sustainability	Authors' comments
Environmental Impact Assessment (EIA)	EIA is a relatively standardised framework for environmental analysis of reforms and initiatives, used for more than 40 years and obligatory for project evaluation within the European Union. A thorough guidance exists, and the EIA has even its own research journals contributing to further methodological advance. The ambition of the approach is to assure that environmental impacts of projects are taken care of	Limited to the impacts of one pillar only: environment. It may address the effects on operational, tactical and strategic levels
Ecological footprint	Ecological footprint is the name of an approach that elaborates an estimate of the level of productive farmland and water that is needed in order to produce the resources we consume and to absorb the emissions that result from consumption. This approach is well suited for comparing projects across sectors; it does, however, solely measure limited aspects of the environmental impact	Limited to the impacts of one pillar only: environment. It may be applied within the context of operational (design), tactical and strategic levels
Life Cycle Assessment (LCA)	LCA is a methodological tool used to measure the overall environmental impact of projects, based on a common unit of measurement that is not monetary. Emphasis is laid on capturing all impacts throughout the lifespan of the project, ‘from cradle to grave’, including impacts stemming from the procurement of raw materials necessary, from the production and distribution of manufactured goods, from the use phase and handling of the resulting waste. In this respect, it resembles the EIA, but is more standardised. Norris (2001) described the differences between the LCA and the LCC	Limited to the impacts of one pillar only: environment. It is usually applied to guide decisions within the context of the operational level only: in the project's design process
Life-Cycle Cost (LCC)	LCC is a methodological approach to assess all costs over the whole lifespan of an investment project. This approach is used for consequence analysis of different design alternatives, either for limited components or for the whole project. Such analysis is becoming increasingly widespread, for instance in the construction industry, and proves especially important in cases involving the cost-efficiency relationship between the investment and the operations (Bjørberg, Larsen, and Øiseth 2007). The LCC can also be considered as a part of a wider economic analysis	Limited to the impacts of two pillars only: economy and environment. It is usually applied to guide decisions within the context of the operational level only: in the project's design process
Financial analysis	Financial analysis is a methodological approach assessing the possibility for financing the project (investment cost and operations), with a corresponding financing strategy and plan for how the annual costs are to be met. Such an analysis can be divided into several components, in that a project can be partly financed directly by the users (e.g. toll roads), while the rest is financed by public funds. The level of user contribution needs to be realistic, especially with attention to possible altered behaviour as a response to the levying of a toll. Equally, public funding is not entirely predictable, being based on budgets that are normally adopted on a yearly basis. Public–private partnership and other forms of organisation can alleviate the field	Limited to the impacts of (almost entirely) one pillar only: economy. It is usually applied to guide decisions made within the context of strategic and tactical levels only
Cost–Benefit Analysis (CBA)	CBA is a systematic process for calculating and comparing benefits and costs of a project, to examine whether the benefits outweigh the costs, and thereby to determine whether it should be implemented. All benefits and costs are expressed in monetary terms (economic, environmental and social impacts) and we can therefore address the ‘net benefit’ flows. Benefits are estimated according to a willingness-to-pay principle. All benefits and costs are adjusted for the time value of money and expressed in present values. See any textbook on CBA, e.g. Boardman et al. (2010)	Impacts of all pillars are in principle included and weighted against each other. It is normally applied within the context of the tactical level
Scenario tools	Scenario tools are conceptual tools enabling the understanding of possible development structures in complex systems for the assessment of economic impacts and future needs relating to an investment project. Different approaches exist, most of them being based on workshops and cross-sectorial participation. Computer simulation tools and models equally exist that serve to simulate trends. The results form an important input to reduce risk and uncertainty. Scenario analysis is often used as a tool for strategic planning, not only in projects. See, for example, Fahey and Randall (1998)	Often limited to the impacts of one pillar only, depending on application. It can be applied to guide decisions made within the context of strategic and tactical levels only
Technology assessment	Technology assessment is not a term that denotes an analytic tool, but rather a tradition of analysis being introduced by the establishment of the Office of Technology Assessment in the USA in the 1970s. The aim of the procedures is to introduce a cross-sectorial and long-term analysis concerning the societal implications of introducing a new technology. Technologies under development form the main centre of interest (Banta 2009)	Technology assessments are usually not applied to guide project decisions, but can be used to guide policy formulation
Needs analyses	Needs analyses are pertinent to the assessment of public investment projects. They can be categorised according to their purpose, such as normative, demand-oriented (economic analysis) or interest-group analyses. Normative needs analyses are based on political consent and expert assessment of reasonable levels of assistance. Demand-orientated analyses investigate the willingness to pay by user groups for the project, while interest-group analyses examine the parties' understanding of their own needs. Næss (2005) recommended combining different approaches in order to achieve a certain method triangulation assuring proper analysis	Needs analyses may be used to map stakeholders' interests and priorities pertaining to the effects of the project on operational (design) and tactical levels. It can also be used to guide policy formulation
Multi-criteria decision analysis	Multi-criteria decision analysis can prove pertinent to comparing different investment projects that are not necessarily presented according to the same scale. The Sustainability Impact Assessment is one of these, but several alternatives exist that quantify and weigh results up against one another based on scores determined subjectively based on objective, quantifiable data, such as noise and travel length, as well as assumed subjective values, such as health and safety. See, for example, Concept Report No. 18	This analysis is highly subjective and rarely conclusive as different effects on operational, tactical and strategic levels are usually hard to compare and prioritise
Stakeholder analysis	Stakeholder analysis: most methodological approaches to sustainability assessment can involve stakeholder participation, ranging from consultative rounds to active involvement in the analytic process and evaluation. As the comprehension of the importance of stakeholder involvement increases, a range of tools and methodological approaches are developed in order to capture the opinions of and involve interested parties. These tools range from ICT-based communication, via personal interviews, to large-scale conferences and meetings. The aim of the analyses can equally range from mapping of points of views and needs, to active involvement in decision-making	This analysis is commonly performed as one of several steps to secure projects' relevance on operational and tactical levels. In some cases, such analysis can have an impact on policy formulation
Corporate Social Responsibility (CSR) and Corporate Governance	CSR and Corporate Governance are approaches from the private sector developed in order to render visible the societal role of enterprises. The relevance of such approaches to public investment projects must in our opinion be considered as limited, but their ambition to illustrate alternative goalsof an organisation rather than only profit make us note them. Some private organisations elaborate so-called sustainability reports or environmental reports that are attached to the annual accounts	CSR and Corporate Governance are not applicable to projects as such, but are usually applied for the formulation of business strategies and the profiling of companies that are responsible for the operational phase of projects only

Note: The comments are made on the basis of the opinions of the authors only.

3.7 Uncertainty, risk and flexibility

Regardless of how sustainable the investment project will be over a time frame, altered framework conditions or technological development can render the investment project unfit for satisfying the initial needs. This is independent of whether the original user group needs to remain unchanged. For example, a risk analysis in the form of a real option analysis ought therefore to form an integral part of ex ante sustainability assessment. Real options provide the flexibility to alter the project design and/or the use of the project. Different kinds can be envisaged: delaying implementation, successive implementation phases (permitting for scaling the project to the real demand) and termination or liquidation possibilities (Figure 2).

Figure 2 No investment project is free from uncertainty and risk. Similar to sustainability, uncertainty takes on different meanings depending on the cause–effect level in consideration. The assumed effects at the different levels are associated with different risks generated by the environment outside of the control of the project as the Logical Framework Approach matrix illustrates. To secure the project from failing to fulfil its objectives, the risks have to be assessed systematically and flexibility should be built into the project design. This figure is freely based on sources written by Samset (2003, 2010).

4. Discussion

Investment projects that prove sustainable at an operational level can still be unsustainable at a tactical or strategic level. By grasping this main idea, we can provide the vocabulary that prevents the construction of landmine factories with sustainable doorsills and stops car sellers from claiming that oversized 4 × 4 luxury cars are sustainable because they have soft drink holders made from recycled plastic. As Clift commented (2003, 243), ‘It is of little interest to you that your killer uses “environmentally friendly” lead-free bullets’.

As we have argued, the concept of sustainability is not identical when comparing cases where experts assess what investment project alternative to select in order to fulfil the general policy of sustainability, and cases where experts examine how to render the chosen investment project as sustainable as possible. There is a considerable difference between analysing whether sustainability is best assured by improving transport infrastructure or other investments (strategic level) by a high-speed railway or a major highway (tactical level), and the assessment of which asphalt qualities within one of the alternatives can be considered to be sustainable (operational level). Obviously, this is not undermining the importance of any of these approaches. They refer to different levels of the proposed hierarchy, and questions pertaining to sustainability must – consequently – be expected to differ accordingly (Figure 3).

Figure 3 Assessment of sustainability must be based on all three pillars (the circles represent economy, environment and society) at all the following levels: project output level (contracted delivery – operational level), goal (target group level – tactical level) and purpose (greater societal level – strategic level).12

Currently, there exists a general agreement in the literature that sustainability may be characterised as a balancing act weighing economic, social and environmental concerns up against one another. Our discussion on the definition of sustainability enables a more tangible understanding of this balancing act, as we propose balancing at the operational, tactical and strategic levels.

At a strategic level, the choice of whether or not to construct a road includes questions such as: does the society, in general, benefit from increased transport capacity in the proposed local area? Are roads the best transport solution from an environmental perspective? Will the construction of the road lead to the intended economic growth? Will the local businesses be threatened by improved access to centralised institutions and is this effect on the local society acceptable to the greater society? Will the project require balancing of international versus national concerns, or balancing of national against regional needs?

Correspondingly, tactical considerations need to be included. They can include questions such as: where to lay the road in order that the impact on environment rests limited? Depending on the type of the investment project, tactical balancing acts will include weighing of local versus regional and national interests, and the needs of identified target groups versus that of the larger society.

Finally, at an operational level, weighing needs to be carried out equally, balancing concerns of economic, social and environmental nature. It is at an operational level that questions concerning the choice of sustainable asphalt arise. Generally speaking, depending on the type of the investment project, such operational balancing acts will weigh durability and suitability against costs and emissions.

Different questions relate to the different levels of sustainability assessment. It is essential to bear in mind that the different levels correspond to different roles that express different interests. On the one hand, the questions concerning the strategic level refer to strategies expressed in valid policy documents issued by financing government offices and agencies. On the other hand, at the tactical level, the needs will typically be defined by local politicians and government offices (project owners), local interest groups and other local stakeholders. The operational level will typically be dominated by architects, consulting engineers and contractors.

This does not imply that for instance architects playing a role at the operational level, do not have a say on the basic concerns on the other levels. Policy makers may have good reasons to insist on specific operational specifications (supporting specific product development programmes on which the strategic sustainability of the project is dependent). Correspondingly, practitioners will often be faced with the need to inform policy makers and strategists of, say, unwanted by-products of the production process that might undermine the sustainability of the whole investment project. The need for cooperation and coordination between policy makers, planners and practitioners will persist.

5. Conclusion

In conclusion, it is well known that it is important to balance the economic, social and environmental impacts of an investment project to render it sustainable. We emphasise that assessments of sustainability in addition should be discussed on three levels: operational, tactical and strategic.

Policy makers will often have differing ideas of what is most important to realise – and to avoid – in an investment project. Correspondingly, the operators and the intended users of the investment project will also have differing ideas. As far as sustainability is concerned, a categorisation into economic, social and environmental impacts makes sense. In addition, the involved parties will probably feel a need for discussing sustainability from the strategic (especially the policy makers), tactical (especially the users) and operational perspectives (especially the operators). The economic, social and environmental impacts can appear at the strategic, tactical and operational levels. Sustainability assessments need to be sorted out on what levels the different impacts appear, in order to avoid the comparison between apples and oranges. Apples are apples and economic impacts at the strategic level are economic impacts at the strategic level.

We have listed some of the common tools for sustainability assessment. The tools vary with respect to what levels they look at (operational, tactical and strategic). At the same time, they vary with respect to whether they consider impacts within one, two or all three pillars. If an assessment of sustainability is clear concerning what level and within which pillar each impact appears, this will improve the value of the assessment. It will be easier to weigh the impacts up against each other and compare them before making the necessary trade-offs between the negative and positive impacts.

Notes

^1. Email: [email protected].

^2. Email: [email protected].

^3. Email: [email protected].

^4. Here, we use the term ‘large public investment projects’ to describe projects that are subject to the Norwegian QA regime, initiated by the Norwegian Ministry of Finance. Today, public investment projects with cost estimates surpassing NOK 750 million are evaluated in this external, two-gate QA scheme. More information on the Norwegian QA scheme can be found at http://www.concept.ntnu.no/qa-scheme.

^5. The most quoted passage from this report, whose official author is the World Commission on Environment and Development, defining sustainable development as development ‘that meets the needs of the present without compromising the ability of future generations to meet their own needs’ (1987, 16), illustrates this differentiation. The definition encompasses very broad societal processes. It is difficult to translate these processes into single ventures, such as public investment projects.

^6. Two parts form the Latin verb sustinere, notably tenere, i.e. ‘to hold’, and sus, i.e. ‘up’. On the whole, we can see that the two conceptions thus form an idea of upholding something. Such a direct comprehension of the concept of sustainability proves problematic, since not only profitable/beneficial but also highly unprofitable and/or damaging processes can be maintained over very long time.

^7. A wide array of definitions exists. In fact, their multiplicity does not only illustrate how complex the concept of sustainability is to define, but also the need for a commonly accepted definition. Hasna (2010) enlisted 67 definitions from the plethora available (strangely omitting the Organisation for Economic Co-operation and Development (OECD) definition, which constitutes the framework of our work). Our preference for the definition of the OECD stems from the possibility to operationalise it into investment project sustainability assessment practice that we have not found in other definitions.

^8. It is on the basis of this ambiguity that the alternative definition of the Norwegian Ministry of Finance seems to have been forged, for which the sustainability of an investment project is defined as: ‘[t]he degree to which the investment contributes to the realisation of goals and purposes after the project is realised and through the expected life cycle. A consideration of net benefit flows over time’ (our translation; Norwegian Ministry of Finance 2008, 5). As it can be seen, the main difference between the two definitions is the replacement of the term ‘benefit’ with those of ‘goals’ and ‘purposes’. The term ‘goal’ is understood as the effects from the user's point of view (Samset 2010, 23). The term ‘purpose’ indicates the long-term consequences of the project (ibid., p. 24). This replacement has the advantage of highlighting that the benefits – according to which the sustainability of an investment project is to be assessed – have to be referred to different levels of analysis.

^9. The insight that assessment of sustainability ought to take into consideration the given context of the assessment is, in fact, not new. As Clift (2003, 241) commented, ‘[i]n formulating and estimating the values of [sustainability assessment] indicators, it is necessary to distinguish between application to “in house” activities and to complete supply chains’, or in other words, that having regard for sustainability means different things when used in different contexts. Clift did not, however, elaborate on the theme, nor did he pursue this insight into the analysis of the project in its context.

^10. For a discussion on the visual representations of sustainability, see Adams (2006).

^11. The term ‘triple bottom line’ refers to the quantified conceptualising of the balance between the three pillars, as introduced by John Elkington in 1994.

^12. Similar categorisations of activities and their objectives into hierarchy levels can also be found in other literature sources. OECD (2002) discussed the Logical Framework Approach with input, output, outcomes and impact. Within the context of corporate business, Mintzberg (1994, 61) elaborated strategies into a hierarchy, with the corporate strategy on top that is supported by business strategies, which again are supported by functional strategies.