Dealing with uncertainties in the design phase of road projects

2.1 The design phase of construction projects

Design is a process; usually, most designs are not done before execution begins, and there is often an overlap between design and execution (Smith et al., 2006). The design process balances clients' needs and actual understanding of project execution. Misalignment always exists between the risk and profits of designers and clients. On the one hand, designers want to benefit from the design; on the other hand, clients want the best design. Therefore, designers should balance between profit and the best design for the satisfaction of both parties (Lohne et al., 2017).

Design management includes determining consultants' duties, resolving project content, planning, resourcing and determining deliverables and controlling and interfering when project objectives are not met (Chapman, 2001). Design process characterise with iteration, using simple ideas for testing solutions, having sequences as design phases, sequences for information exchange and the influence of external agencies and client changes (Chapman, 2001; Johansen et al., 2019). This process is seen as communication between problem and solution aided by the three activities of analysis, synthesis and evaluation (Lawson, 2006). The road design process could have the following steps: feasibility study and preliminary design and detailed design based on the study by Rwakarehe and Mfinanga (2014). Design is not a logical and tidy process in projects and is semi-messy (Lawson, 2006) and wicked problems with no single solution but multiple solutions (Buchanan, 1992).

Different demands and requirements in the project's design convey many challenges for involved parties. Lohne et al. (2017) represented the ethical concerns practitioners meet in the design phase of architecture, engineering and construction (AEC) projects. The most important challenges mentioned were hidden agendas and power actions from different parties. Therefore, the parties need to acknowledge that various requirements and interdependencies in the design phase need to be handled. The design phase is an ongoing and continuous process (Lawson, 2006). It could have uncertainties related to lack of constructors' cooperation (Samset, 2010), setting more ambitious projects goals, ill-defined project scope and weak design (Johansen et al., 2019), inappropriate design, poor engineering, delayed in design activities, delay in buying land and change in raw material cost (Smith et al., 2006; Mhatre et al., 2017) as well as lack of designers' involvement in the primary decision process together with the owner, which might lead to organisational risk (Jaafari, 2001).

Projects with high technical, procurement and contract complexity require careful design. Besides, political, economic and environmental issues also influence them (Johansen, 2015). In other research by Asadi et al. (2018), they found that shortages in design documents could affect safety performance and construction projects negatively. Thus, design consequence develops in later project phases, and design difficulties rely on project complexity and the project type, which could be different. Early management of design uncertainties may mitigate these effects.

2.2 Uncertainty management

Galbraith (1974) said that uncertainty stems from a lack of information. He explains that uncertainty undermines firms' ability to plan proactively and make proper decisions before project execution. Risk and uncertainty are used interchangeably in which risks are related to something negative, and uncertainty is a negative or positive event that has been identified but is unknown (Ward and Chapman, 2003; Walker et al., 2017). Many authors declared the relationship between uncertainty and risk in the literature on uncertainty and RM (Jaafari, 2001; Johansen et al., 2019).

Risk is part of uncertainty with negative consequences on the project's objective. It will be an opportunity with positive effects (Wideman, 1992). According to Thamhain (2013), many managers spend much time on risk-related issues in the projects' early and design phases. Perminova et al., (2008) said that uncertainty “is an event or a situation which was not expected to happen, regardless of its prediction”. Uncertainty is when established facts are questioned and thereby the basis for calculating risk (known negative event) or opportunities (known positive events).

According to Winch (2010), uncertainties can be defined on a spectrum from “known knowns” to “unknown unknowns”:

1. Known knowns: According to identified risk source, a probability can be assigned to the occurrence of the risk event;

2. Known unknowns: The risk source has been identified, but the probability of a risk event occurring cannot be determined;

3. Unknown knowns: Risk source and associated probabilities are known but kept confidential and

4. Unknown unknowns: No risk source and risk event have been identified.

The range of growing uncertainty from “known knowns” to “unknown unknowns” distinguishes risk from uncertainty and unexpected events, which connects the concept to the availability of information and decision-making.

Chapman and Ward (2007) defined five preliminary questions in addressing uncertainties: “Who are involving parties?”, “What are the motives of the parties?”, “How is it to be done?”, “What resources are required?” and “When should it be done?” These are main questions for tackling uncertainties in each project's phase.

Each phase may call for different ways to address uncertainties. For example, price increases of construction materials for building a bridge in the initial phase cause owners to consider higher contingency or contractors change their suppliers to find low prices suppliers and compensate the cost or look for cheaper solutions. This uncertainty in the execution phase might need different strategies such as cost-cutting tasks, reducing unnecessary work and changes in design.

2.3 Criteria for uncertainty management

Figure 2 depicts the Johansen's (2015) theoretical framework utilised in this paper, with “human and organisation”, “processes” and “tools and techniques” as the three main UM components. All three need to be functional and work together if “living uncertainty management” should be obtained in the project's design phase.

Klakegg et al. (2010) suggested that for conducting uncertainty analysis, both the sophisticated criteria associated with “good” and the practical options associated with “simple” are needed. He noted a tendency towards more complex tools and techniques; this might be due to larger and more complex projects over the years. Zidane et al. (2013) identified project characteristics that serve to differentiate between small, medium, large and megaprojects. These include the budget, the timeline, the number of stakeholders and the complexity level. These characteristics might help decide the complexity level in processes, tools and techniques and organisations. This section describes criteria with three components of human and organisation, process and tools and techniques.

3.1 Literature review

As shown in Table 1, a systematic literature review started with selecting important keywords for study topics. We investigated human and organisation, processes and related tools and techniques of UM. To decide the different literature's relevance for this paper, one of the authors searched all journal articles in all issues (2015–2022). The search concentrated on databases Scopus, Web of science and Emerald as illustrated in Table 1. In the first step, articles were filtered based on search keys in title-abstract-keyword, journal articles, English articles and peer-reviewed articles. In the second step, abstracts of the papers were read, and articles were chosen based on the inclusion criteria with a focus on three components of UM and RM models in construction, infrastructure and highway projects. The numbers in the last column of Table 1 show the total number of articles after reading the abstract. Then in the third step, abstract and conclusion of the articles were read and data were reflected on paper.

The number in the parentheses indicates the articles that can be accessed by reading the abstract. The inclusion criteria in the third step were if the result was relevant to uncertainty framework, models and components of UM or RM in projects. All articles (45) were read and reflected upon in the introduction, theory section and discussion.

3.2 Choice of research method

Yin (2018) suggests using case studies and histories to answer how and why questions and explanatory research studies. Multiple case studies allow the evaluation of a phenomenon in different situations. Case studies help understand case complexity, such as changes over time, the work processes and the interaction of different parties. A case study also facilitates grabbing the project's contextual condition (Yin, 2018). RQs in this study seek to know how uncertainties are managed in the design phase, identify key criteria for UM framework and how relevant framework components play a role in UM. The research is a case study as a qualitative approach which uses empirical data, a document study and interviews to answer the RQs. The process of UM was not examined in detail in the design phase of Norwegian projects, and we required some criteria for determining its performance. A case study involving two cases with two different owners was the most appropriate way to understand the complexity of cases. This helps to compare cases and evaluate them with identified criteria.

Researchers can see differences and similarities between the two cases, and the data are more reliable (Baxter and Jack, 2015). Two cases were homogeneous in the context of the project's operation. This study analyses and verifies theoretical propositions using theory and data. Triangulation is a research strategy using different data sources (Bryman, 2016), and we used this strategy for data collection to improve the findings' reliability. Table 2 illustrates the characteristics of two road projects used for data collection. We conducted semi-structured interviews as part of the data collection.

The two cases studied are large projects. Both cost more than US$150m, have many stakeholders, medium to high complexity and medium/high uncertainty about the design and execution phase. Both projects had two different owners in Norway. The description of the studied cases in Table 2 is as follows:

The new cable bridge is going to replace an old bridge. The estimated project cost is around US$150M, and the bridge will be connected to a new tunnel. The old bridge will be replaced by a new pedestrian and bicycle bridge. The new 183-m-long bridge with a tower will be presented as a landmark in the city, which increases the project's importance. The project includes a 1.2 km of road, 2.1 km of ramps, 570 metres secondary roads, 1.7 km bicycle road, 14 constructions and a 160-m tunnel. The construction includes a new road, two new bridges and an old bridge will be updated and changed to a pedestrian and bicycle bridge.

The old road was a corridor and part of the national transport network with many problems related to safety and traffic with a high risk of accidents which needs to be improved. The estimated cost of the project is around US$621m. The new four-lane road will replace the previous two-lane road. Higher speed limits and a shorter length, together with higher quality, will reduce travel time and increase safety on the highway. This project has four double tunnels and the road length is approximately 19 km.

3.3 Document study

A document study was performed to get information about project characteristics, important uncertainties related to the two case studies and project uncertainty analysis processes. Document study was a preliminary study before doing the interviews. There are some sources of risk documentation in non-traditional ways: interactive websites, digital media, video reports, workshops, chat rooms, wikis, discussion groups and electronic files.

In the process of document study, experienced authors, at the first step, choose the related documents. Then each author reviewed the documents and wrote the project's description and related information from meetings during the project's design phase. All these documents are publicly available and do not contain confidential information. During the research process, information was completed with new documents in contact with project parties. The studied documents are presented in Table 3:

3.4 Semi-structured interviews

Semi-structured interviews can be conducted by developing an interview guide covering specific topics. The interviewer is not obliged to follow the interview guide; sometimes, the interviewer could ask some questions that do not exist in the interview guide to get a better insight into the topic (Bryman, 2016).

After the pre-interview, note-taking and recording are utilised to collect data. The cases differed; experts interviewed client project managers, winning contractors and designers. Interviews lasted one to one-and-a-half hours, depending on the interviewees' schedules. We used coding based on essential criteria for each UM component for data analysis. For instance, we chose documentation-level, formal or informal, information exchange for the process component. Table 4 shows the paper's interview process and provides information regarding interview duration, interviewees' role in projects, data collection method and follow-up meetings or contacts with interviewees.

We interviewed about the UM process, tools and methods and related criteria. We asked about people involved in the UM process during the project's design phase and how they acted in such a process. Seven interviews have been conducted for two projects.

4.1 The human and organisation component in the design phase

Case 1 document examination indicated that various stakeholders, health, environment and safety (HES), geotechnical consultants and owner design managers participated in UM. The owner's UM process is built on group work led by a competent facilitator (competent: based on experience and education) who has taught people to manage it. All members of UM team conduct risk registers throughout various periods.

The contractor collaborated closely with a client in UM. The owner selected the contractor through a design contest. For example, near the railroad, the railway and design consultants, the builder (owner), and the general contractor all participated in risk analysis sessions. Before evaluating the design, they meet with six or seven competent individuals linked with the uncertain issues. The owner said:

We chose a highly qualified contractor based on price, experience, and design competition. Besides, the people in our team have enough experience in UM process. Senior managers support choosing competent people in our team and the contractor. Organization have some guidelines and procedures for choosing qualified contractors.

The contractor said that:

Different roles were involved in the UM’s meeting with competency in their tasks. Their competency was based on the years of experience and the successful project they conducted

Built on the contractor's interview documents with famous magazines in transport and infrastructure, the contractor affirmed their abilities and risk-taking behaviour, which denotes competency by saying (Holm, 2021):

We have previously carried out major infrastructure projects in the city and have a group of people with local affiliation who want to help to make Trondheim a better city to live and travel in.

Consultants said that,“Our team members are not involved in formal meetings for UM, and we follow our UM independently based on our requirements”.

The approach for picking a competent contractor relies on a repeated iterative design process until the owner selects the optimal solution. Risk and uncertainty ownership was outlined in the contract, and the owner said that:

We were responsible for safety management at the project level and strategic uncertainties. At the same time, the contractor was responsible for safety at the operational level.

In both cases, people with varied expertise and competence in UM project team are involved. They lacked a dedicated role for UM, and the project manager on the owner side was responsible for UM with other experts such as economy experts, planners, construction managers, and assistant project managers. In addition, an external expert was selected to manage UM process and meetings. Case 1's UM confirmed efficient communication with various participants. Interviews with the project owner and contractor indicate a satisfying level of communication. For instance, during COVID-19, they conducted various virtual meetings (such as technical meetings) with appropriate digital tools. They observed information exchange between actors. The owner said they had consented with property owners to use the land within the project path. The project manager (owner) stated:

For technical risks, we had regular meetings during the design phase with contractors and designers, and they were independent of design meetings. We recommend people use collective transportation more on heavy workdays in the project route to reduce the traffic in the area.

In Case 1, the consultant (designers) analysed projects based on document examination, owner meetings, and questions about the project. They directly studied the project site and created documents based on their observations and opinions. Processing an agreement with neighbours and landlords or relocating residences from the project field to other regions. In an interview, designers indicated that:

Project owner successfully managed neighbours (environmental factors) and land acquisition.

The explanations provided by stakeholders demonstrate the level of contact with various parties, including third parties, contractors, designers, and end users. Communication level with designers and their participation in the UM process indicated a lack of consultants' (designers') ownership of project risks. Consultant said:

We are not involved specifically with UM in the design phase. But in new projects, it becomes common that consultants work with uncertainty systematically.

In Case 2 UM's meetings were conducted with sector authorities, municipalities, and owners. These meetings were evaluated positively, issues were highlighted, and the contractor could present various solutions (the contractor was responsible for the design). The contractor participated early in the project and gained ownership of solutions. Sector authorities had a positive impression of their cooperation. The support for UM in the project team by the organisation and top-level managers (both by owner and contractor) was confirmed. This support indicates a supportive culture of the organisation for UM practice and its importance.

The owner organised risk and uncertainty analysis meetings every two weeks with the contractor. The owner confirmed the effective communication and competency of the contractor verbally. The owner said that:

We evaluated solutions (design alternatives) provided by the contractor, and according to their experience, prices, and track record, we chose them for this project.

Owners undertook their analyses personally and examined numerous facets of risks and alterations, and the contractor validated this cooperation. For instance, when they decided to make a design change, they consulted with designers, lawyers, and geotechnical engineers to analyse it from several angles: In an iterative process with the owner, the contractor made changes until the owner was satisfied with the result. The contractors have internal meetings informally (without a plan beforehand). The contractor focusses on operational risks, and the owner focusses on business-level risks. The contractor focusses on HES-related risks, operational risks and force majeure events.

The contractor should deliver weekly risk reports to the owner. They share their internal risk register at the HES and operational level with the owner, which implies satisfying communication and information sharing between them. They had a common risk register with the owner at the overall level. The contractor's project manager has long years of experience in UM. Consultants in Case 2 are involved in issues that require design or plan changes and should submit their suggestions to the owner or contractor. Consultants just provide a detailed project design and deliver it to the contractor. The designer said,

We are not involved in the formal UM process, and we had only our internal UM, which focuses on our daily tasks.

The contractor was responsible for the project design. They confirmed information sharing with the owner, demonstrating the two actors' trust level.

4.2 The process component in the design phase

UM on Case 1, based on the project owner's guidelines, are as follows: (1) defining goals and execution strategy; (2) identifying uncertainties; (3) qualitative evaluation; (4) quantitative assessments; (5) managing risks reducing consequences and sharing risk, transfer, insure against risk and accept (6) managing opportunities; (7) monitor and control and (8) communicating and reporting (Veidirektoratet, 2011). This UM procedure was the same in both cases (1 and 2).

The owner led and controlled the UM process in Case 1. Priority-based measures are developed to address the identified threats and opportunities according to design solutions. The owner said,

Regarding observed risks, resources are allocated, and actions are taken until the risks and consequences diminish. We are more concerned about risk than opportunities. The contractor said that we mainly focus on risks and consider opportunities but not as much as risks.

The owner stated that they have a formal process with the contractor every three months during the design phase. The contractor's role in RM is (chromatic) bold in this project. Consultants (designers) are not actively involved in the projects' UM process. However, consultants (designers) conducted all the projects' detailed engineering and used owners' guidelines. They do not have any formal process for their UM, but they emphasise the owners' formal role. The consultants stated,

We have different uncertainties in our daily work which we decide and tackle daily and informally.

The project manager in Case 1 believes that the formal meeting for UM is held twice a year. However, the actual UM process is systematic and is conducted daily during the project because they believe all the problems they found during the design phase are somewhat related to uncertainties.

Case 1's owner and consultants met with the railway authority to mitigate railway-related risks, indicating formal process and collaboration. The construction site is close to a heavily travelled roadway. In their qualitative risk assessment analysis, all risks were deemed acceptable, and a risk-mitigation strategy was developed for each risk item (Sivalingam et al., 2018).

Their strategy in the design phase was to identify uncertainties and “dive into matters” in a friendly and collaborative environment with the owner. This process directs contractors into the entire process of the tendering phase, and they evaluate clients' risks, see the big picture and define risk-reducing measures. They see the important uncertainties and biggest expected challenges in the project execution. Simultaneously, they go through the negotiation phase with the client. In the bidding process, they check all the risks. The contractor said,

In preparing the first proposal, we checked all the risks and opportunities and found construction client risks to know what changes we should make to achieve a specific price. We believe each project has its project-specific risks and opportunities; our focus was mostly on risks rather than opportunities.

The contractor said that they follow a standard process for each project. First, they have a heatmap with a sheet that records what projects contain. Second, they have an application for getting permission to use resources. They defined the five most significant uncertainties and calculated their risk and opportunities. They had six meetings (for checking registered uncertainties in the system log) with the core uncertainty team before preparing an offer to the owner. Besides, they should fill out the owner's risk matrix. Sometimes they receive some pointers from the owner's side, which say:

Yes, but we perceive this as the contractor’s risk.” This negotiation happens during “bid evaluation” to accept the contract.

The above quote was an example of information exchange between owner and contractor and sharing risk during formal meetings. After delivering the design to the contractor, owners share less information with designers and consultants.

The ability to support prioritising risks and assign resources to a contractor in critical risks depends on the relationship between owner and contractor and the predefined procedure for UM. Contractors affirmed,

There is no clear line between ours and the owner’s risk. The contractor explained that they conducted an uncertainty analysis early in the bidding process. The design was delivered to the contractor completely, but they made changes during execution and presented their proposal to the owner.

Stemland et al. (2021) explained that the UM process included describing the planning area, identifying possible unexpected events, risk assessment and vulnerability, identifying measures to reduce risk and vulnerability and documenting the analysis and its effect on the project plan. In the zoning plan, design alternatives were defined and evaluated to choose the one with a lower possibility of risk for the project's goals.

Case 2's project contractor stated during the interview that they were liable for the project's UM. Within the scope of his remit, the project manager is the decision-maker for addressing operational risks connected to progress and the economy. In Case 2, the owner meets with the contractor every two weeks (confirmed by both parties) to assess risk and uncertainty jointly (formal UM process). The contractor must notify the client of the error before the deadline. Otherwise, the contractor (designer) should accept the risk of design flaws. Depending on the contract and risk category, the owner shares risks with a contractor. For instance, the ground condition is the owner's risk as other aspects of the contract's requirements.

The contractor, in the interview mentioned the collaboration level with the owner and other actors by saying,

The level of collaboration and information exchange with the owner was satisfactory, and all parties participated in meetings. We trust and the owner shares the risk register platform with us. But there exists less information sharing with consultants.

According to the contractor, uncertainty is not formally discussed regularly. The contractor said,

The day before discussions with the owner, we hold internal meetings and review newly detected risks or modifications to previously recognised concerns. Uncertainty is not a phenomenon we formally evaluate, but informally we evaluate it daily.

The operational-level risk register system of contractors differs from that of the owner, yet they share information. UM is the key activity in the contractor's management system since they seek to find opportunities or cost-optimisation alternatives to meet the owner's budget (shows contractors' competency). Between project meetings, they hold meetings to select one alternative for design with a comprehensive exploration of alternatives. For instance, consultants travel to the site to assess the ground condition. In Case 2, consultants attended project meetings but were not actively involved in the UM process, according to the interview. Consultant commented,

We were not actively involved in the uncertainty management process, and both owners and contractors were responsible for uncertainty management.

The document study also confirmed this. Contractors provide suggestions or new solutions to the owner for design and plan changes (Værnes and Tunheim, 2019).

4.3 Tools and techniques component in the design phase

Document study and interviews of the Case 1 show that the owner uses a spreadsheet and uncertainty log for risk register, uncertainty analysis and UM. They utilised a tool called “Anslag 4.0” (translates to “estimates”) to calculate the road project's cost, including its uncertainty in different phases (quantitative tool). They have an economy follow-up system called “G-Prog project economics”. Both risks and opportunities can be logged and managed with this application (Vegvesen, 2014). The owner in Case 1 stated,

“Tool's visualisation capabilities should be enhanced, and dealing with tools is somewhat complicated. The tools could provide somewhat precise answers, and track record of a successful project from a cost perspective shows this success. Tools are not resource demanding in comparison with project's cost, but it takes much time and energy to provide input data for the tool”.

The contractor has types of risk registering systems which contribute to outlining what projects contain and how to exploit resources for UM (qualitative). Besides, the contractor had risk register logs during the design and proposal review, and UM's team members have access to the risk registers.

We (contractor) have a system in the company which evaluates the risk and opportunity profile of the project before accepting it.” The system does not have high complexity.

In Case 1, designers followed the owners' spreadsheets for the design competition and used owners' guidelines and tools for detail engineering. An interview and document study (Veidirektoratet, 2011) revealed that the register systems are qualitative; later, they calculate the consequences in cost for each item separately, which helps them to quantify the results. They said,

As designers, we do not utilise the system that the owner and contractor use.

Case 2's owner stated that the project's design complied with integrated concurrent engineering (ICE) sessions. They successfully made it paperless and BIM enabled. The Case 2 interview with owners demonstrates that they have a complete and adaptable web-based application, namely PIMS online, with many tabs and modules for registering and managing risks. According to empirical data, this tool had high and satisfying visualisation capability and documentation. The owner said,

We documented project-related risks and opportunities in the system daily. We have a system for risk registering, and we use brainstorming to identify upcoming risks in the project’s design phase.

We utilized qualitative and quantitative tools, adding complexity to its understanding. We have a scoring system for each risk and determine its cost. The system we are using has some complexities in calculations and quantifications.” The tool is not resource-demanding compared to project cost and is easy to use, but feeding subjective data to the system could take some time and thinking.

They have various alternatives for projects, and they try to detail, evaluate and choose one of them. It's possible that, after selecting one alternative, they realised it was incorrect after more investigation. Case 2 document analysis and empirical findings demonstrated the contractor's early involvement in the project and ownership of the solutions. Sector authorities had a positive impression of this type of cooperation. They used a risk matrix for identifying risk relying on the owners' risk documents (Stemland et al., 2021). According to reports for the project's section, with high uncertainty and nearby the railway, the triple estimates of quantities and unit prices have been used as input values in the analysis. Consultants have included uncertainty factors in the analysis, and the results were obtained through Monte-Carlo Simulation. Both owner systems had good visualisation, allowing them to follow risk from red to green zone (safe areas). With visualisation, they can prepare reports on different dates and track changes.

Consultant's cost estimates were based on builders' and owners' estimates (Sivalingam et al., 2018). Based on empirical data, the consultant also fills out the project's risk matrix and sends it to the owner and an offer for the design competition. The owner's prepared forms of the risk matrix had no room for an opportunity register, and the focus was on the risks.

5.1 Uncertainty management in the design phase

In the design phase, actors prioritise clashes, most probably when they are suspected of following their agendas rather than general project objectives. The design process is a crucial linkage point between the expressed needs of the client and the actual realisation of the construction project. From one perspective, owners seek to avoid such extra cost and time (project outcome) as important parameters of UM and to have better solutions (design outcome) through an iterative design process. From another perspective, designers and consultants think long term. Better design means longer cooperation and more opportunities for future work. Therefore, it is a win–win game for all designers, contractors and project owners. Both cases' trust and collaboration levels could signify having a relationship between actors (a win–win game).

Both projects' owners and contractors follow a structured process for UM. They begin the process early and own the uncertainties at the strategic level, which needs competent people and efficient communication between actors. This implies on supportive organisational culture from UM process. For example, the owner accepts ground conditions or price increases (because of COVID-19 or unexpected events such as war) as uncertainty in the design phase early in the process. They know that after the design phase, the project manager might disclose ground conditions modifications that can add extra costs to the project. The owner considers contingencies for these types of uncertainties. Therefore, uncertainty ownership and supportive culture, such as management support, are important criteria in UM of the design phase. Qazi and Simsekler (2021) considered support for prioritising risks and assigning resources to critical risks as important criteria for the UM process.

5.2 Important criteria for uncertainty management framework in the design phase

We chose Johansen's (2015) framework as a theoretical framework. For each component [(a) human and organisation, (b) process and (c) tools and techniques)], some criteria were developed according to literature as relevant criteria for evaluating UM performance. These introduced criteria could not cover all criteria which show or measure UM performance. It is just starting point for knowing which criteria could be considered for UM to become successful in projects. This model was tested with empirical data to know how they play a role in the UM process in the design phase. Although for a better and more precise evaluation, it needs more data from different projects.

The selected criteria reveal the portion of the story. However, they cover significant ones. For instance, communication has been recognised as one of the essential components in humans and organisations. Notable is the fact that communication could be enhanced with better tools and competency. Therefore, these criteria are interconnected and are not independent of the UM process. Three important components also are interconnected in UM. For instance, a process with effective communication needs suitable infrastructure to support it. Owners who follow the formal UM process must have suitable systems and infrastructure to support such collaboration. Efficient UM and successful processes need to have competent people. They are not only independent components, but we could evaluate them independently. The overall performance of UM in projects depends on their performance collectively.

5.3 Practical implications of the research

Project evaluations showed that the choice of skilled people, UM process and suitable tools and techniques for UM depends on the projects' characteristics, stakeholders' collaboration level and owner company's organisational variation. High uncertainty in design influences the contracts strategy of the projects, and they made a competition for a design to find the best solution. For example, having a project constructed inside the city with existing uncertainties and a symbolic structure affects the city from aesthetic dimensions. Furthermore, it directs the owners towards design competition to get a better bridge design result before the project's construction.

In contrast, a large-scale project with long roads and long-time frames with different tunnels and bridges outside the city could direct the owner to involve in more collaborative participation and choose the main contractor with high experience in managing different contractors. Trust could be an influencing factor in such collaboration to monitor the work in all phases and overall have better control over the project. The risk manager in Case 2 also confirmed this collaboration as an open and satisfying relationship (trust). These empirical data were in coordination with Osipova's (2008) findings, which show that an open attitude, effective communication and information exchange supports project risk. According to Karlsen (2011) organisation culture influences and determines the effectiveness of UM.

When there is a collaborative contract between owner and contractor, they share more information and use integrated systems for UM. For example, the study of Case 2 shows more information sharing in risks and uncertainties and having integrated systems in which both sides have access to the system. The integration level in Case 1 was less than in Case 2. When needed, information sharing and collaboration levels can signify trust between owners and contractors. Generally, designers have less information sharing of uncertainties with contractors and owners, which Osipova (2007) in the research confirm the low collaboration of consultants in UM process.

Identified criteria in the paper gave a better insight to practitioners, project managers, owners and policy-makers in the UM process and evaluation of it in the design phase. Project managers will notice criteria such as effective communication, web-based tools, better documentation, visualisation capability and sharing information as important criteria which are interconnected and are important for the design phase. Owners know that early information sharing with designers leads to better product design. The benefits of better design directly are for project owners who will experience lower changes and higher value (fewer cost overruns). For contractors, based on contract type, the result could be different. Policy-makers would comprehend the significance of the design phase and define stringent requirements for projects to pass quality checks. They have an integrated approach with a special focus on UM process, standard tools (such as web-based tools or documentation standards) and important uncertainties (such as ground conditions and market conditions). Quality checks in the design phase enhance road project performance during execution, which directly benefits society.

In this paper, we tried to fill this gap in the literature by developing Johansen's (2015), framework by identifying relevant criteria for measuring UM in the design phase. For instance, Xiahou et al. (2022) mentioned that existing research mostly notices post-accident management, and there is a shortage in pre-management awareness. Therefore, with better pre-measurement, we could expect a better design process with fewer changes and redundant work later. This pre-measurement in the design phase is essential for successful project execution and achieving a better result with lower consequences for unexpected or expected ambiguities, variations and uncertainties. For instance, effective communication, better visual capabilities, information sharing and efficient documentation in the design process lead to better product design.