The Fornebu Metro Line project is Oslo’s biggest and most complex metro project in the last 50 years. To fulfill the client’s key objectives and goals, Target Value Design (TVD) has been applied by Prosjekteringsgruppen Fornebubanen (PGF), consisting of Multiconsult and COWI in a joint venture, in the design phase of the project.
TVD embraces the goal of maximizing the value for the client and the users within project constraints and therefore goes beyond the design-to-cost principle. The iterative process of evaluating value and purpose in design against constraints predefined in the business case distinguishes TVD from other managerial tools.
So why should Norway’s construction industry consider applying this holistic methodology and mentality? One major reason is TVD projects’ convincing track record:
- Projects are completed 15-20 % below market cost while maintaining quality and time.
- Preventing ‘overdesign’ and managing complexity by focusing on common goals and objectives in cooperation with the client.
- Increased accuracy of conceptual estimates.
- Lower contingency needed for each project.
This simplistic theoretical approach seems straightforward. Easier said than done. ‘Value’ is often seen as evolutionary and therefore tends to change over time. Hence, TVD cannot be executed and fulfilled without client and user involvement.
Figure 1: A holistic presentation of how to evaluate value and purpose in the design.
Several distinct TVD characteristics have been highlighted. An article published at the International Group for Lean Construction (IGLC) conference summarized these characteristics to compare the TVD maturity among Norwegian public building projects (Smoge, et al., 2020).
|Setting Targets||Focus on detailed estimates rather than estimating based on detailed design.|
|Work structuring||Design what is constructible rather than evaluating the constructability of the design.|
|Set-Based-Design||Allow several alternative solutions to proceed into the design process rather than narrowing choices to proceed with the design.|
|Collaboration||Emphasize collaborative work to define the issues, produce decisions, and design those decisions.|
|Co-location||Enhance working together in pairs, large groups, or face-to-face rather than in silos and separate rooms.|
Table 1: Five distinct TVD characteristics identified in the project literature.
The question is ‘How’
The Fornebu Metro Line has an expected project cost over 1.6 billion EUR. The project includes an 8.5 km metro line in combination with six new metro substations, as well as a new maintenance and metro park facility. Cost has been the constant priority in this project, which has urged PGF to achieve and create greater value within budget.
Typical causes for underestimation are overrating benefits, insufficient estimation methods, and underestimation of risks to mention a few. To track cost and cost development, the project has integrated an estimation process for each quality level in the Project Execution Model (PEM). Cost target is set for various objects according to a pre-defined Cost Breakdown Structure (CBS). The result is a standardized estimation process where the consequences of decisions made are constantly measured against realistic sub-targets (baselines) for each object. These estimates are also an integrated part of project risk analysis that targets specific high-risk elements.
Cost and design maturity are linked via the Building Information Model (BIM). BIM is used in all levels of design, and the level of model maturity is a powerful tool when integrated into the cost estimation process.
Altogether, this methodology provides PGF a powerful tool to measure and evaluate potential cost deviations. In other words, the project cost is constantly monitored against sub-targets.
Figure 2: An overview of the workflow of how PGF has managed to live monitored project cost.
Standardization is a key aspect to provide more value-adding activities in the project. In this metro project, the optimization process has included creating a set of standardized tunnel profiles, rather than numerous “tailor-made” ones. The benefits of improved constructability and reduction of rework easily exceed the benefits of optimizing every bit of the 8.5 km tunnel to reduce volumes and quantities.
Focusing on constructability is also conducted for the stations. An example is the live tracking of the number of different types of steel or concrete beams and columns to balance cost optimizations and standardization.
Set-based design is, at first sight, counter-intuitive: Why spend the extra resources in producing several alternative solutions or technical specifications up until the ‘last responsible moment’ for them to proceed with only one of them? The answer is clear: Thorough evaluation and cost estimation of each of the alternatives based on all relevant design criteria provides the means to choose the “best alternative” rather than the first. Or put in other words, emphasize the need for a predictable decision-making process based on needs, demands, and objectives:
- When a decision is made.
- The decision basis.
- What the consequences are.
A part of the decision-making process for us in PGF and the client is to use Integrated Concurrent Engineering (ICE) sessions to investigate the consequences for the proposed alternative based on HSE, cost, technical performance, quality, schedule, and contractual considerations.
PGF and the client have ambitious BIM goals. The goal is to integrate information such as commercial requirements, CO2 imprints, bills of quantities, classification, and operation and maintenance information. Digitally integrated design and execution is a necessity to fully exploit collaborative contractual arrangements, such as Integrated Project Delivery and alliance. PGF has received international recognition for its BIM achievements (Irgens & Ganz, 2020).
Co-location is beneficial for efficient collaboration, and PGF and the client share the same office premises. However, as this project follows a design-build contract, the contractor and its subcontractors have not been integrated into the project organization to date. TVD focuses on creating value-adding solutions for both the client and the users by exploiting the expertise of relevant stakeholders in the project, including contractors.
One cannot argue that the project has fulfilled all the characteristics of this holistic methodology. To fully exploit the benefits of TVD, the methodology must be implemented at the very start of the project with the resources necessary. This implies that the client must acknowledge the fact that TVD impacts every phase of a project.
(1) Irgens, C. & Ganz, M., 2020. How to Collaborate on a Mega Metro Project Using BIM 360 and an Open BIM Approach. Digital, Autodesk University.
(2) Smoge, G. Y., Torp, O. & Johansen, A., 2020. Maturity of TVD Implementation in Norwegian Public Building Projects. Berkeley, California, 28th Annual Conference of the International Group for Lean Construction.