Organisation of Large Underground Construction Projects in Germany and Switzerland – A Comparative Analysis

In Germany and Switzerland, the realisation of large-scale projects is always the subject of controversial discussions. The media often give the impression that there is a lot wrong in Germany and that everything is fine in Switzerland. It is therefore investigated whether such an assessment for large underground construction projects is justified according to scientific criteria. For this purpose, a measurement system was developed to evaluate the success of large underground construction projects based on seven success criteria. This system was applied to 70 large underground construction projects in Germany and Switzerland. In addition to a quantitative comparison of the two countries, this article highlights differences with regard to the individual success criteria. The results show that large underground construction projects in Switzerland are not conclusively more successful than in Germany. However, the decisive factor for the respective project success is the quality of cooperation among the project participants.

1 | Selected measurement system with criteria and scale
Credit/Quelle: Escherich
1 | Selected measurement system with criteria and scale
Credit/Quelle: Escherich

1 Introduction

In both Germany and Switzerland, the construction of large-scale projects often causes a stir in the public and the media. It is repeatedly discussed whether the realisation of large-scale projects is more successful in Switzerland than in Germany. Media coverage in both Germany and Switzerland gives the impression that Switzerland plays a certain pioneering role and serves as a role model in the realisation of major projects, while major projects in Germany often fail. For example, the Handelsblatt has the headline: „Why are the Swiss so much better at large-scale projects?“ [1]. This impression is further reinforced by a study by Hammerschmid et al [2], which shows that Switzerland is the European leader in project management of large infrastructure projects, while Germany occupies a mid-table position. In the media coverage, the major projects Berlin Brandenburg Airport, the Elbe Philharmonic Hall in Hamburg and Stuttgart 21 are listed as negative examples for Germany. These major projects repeatedly make the headlines with massive cost and schedule overruns. On the Swiss side, the Gotthard Base Tunnel is often used for comparison, as it is the longest railway tunnel in the world and was completed within the plannedcost and time frame.

However, the success of a country in the realisation of major projects cannot only be determined on the basis of a few selected examples. For example, there are also major projects in Switzerland that can be considered negative examples due to significant cost and schedule overruns. Conversely, there are major projects in Germany that have been successfully realised but have received little attention.

In the media comparison between Germany and Switzerland, large underground construction projects, such as Stuttgart 21 or the Gotthard Base Tunnel, play an important role. Large underground construction projects are challenging and complex with a long project duration and are therefore associated with high project requirements and risks. In the following, the question is examined whether the impression that the realisation of large underground construction projects in Switzerland is more successful than in Germany is justified according to scientific criteria.

2 Measurement System – Scaling and Success Criteria

To be able to answer this question, a measurement system was developed that allows the project success of large underground construction projects in Germany and Switzerland to be measured and evaluated equally [3].The basis for the presented measurement system is the model according to Ehrbar [4], which was developed for large infrastructure projects.  In the here presented measurement system, seven success criteria are defined, which can be measured as objectively and quantitatively as possible (Fig. 1). However, objective measurement is not feasible for all success criteria, which is why a distinction is made between qualitative and quantitative criteria. „Cost“, „schedule“ and „occupational safety“ were selected as quantitative success criteria. Qualitative success criteria include „quality“, „organisation and processes“, „environment“ and „public opinion“. In order to gain a full picture of the qualitative success criteria, these were composed of several equally weighted sub-criteria:

Quality

Guarantee of the stipulated functionality

Time duration/restriction of the renewal measures

Guarantee of the stipulated structural substance

Organisation and processes

Cooperation in partnership

Decision management

Environment

Environmental compatibility

Compensation measures

Recycling of excavated material

Public opinion

Acceptance

Timing/extent of public involvement

Involvement of the public during the construction period

 

A 7-point Likert scale is chosen for the scaling of the measurement system (Fig. 1), which enables the consideration of quantitative and qualitative success criteria in equal measure. The target values of the individual success criteria are based on the fulfilment of the project requirements, so that the fulfilment or the relative deviation from the defined project requirements is evaluated. The scale scores range from +3 to -3, with +3 corresponding to over-fulfilment of the project requirements and +2 to achievement of the target value. The measurement system developed should thus make it possible to fully assess the project success of large underground construction projects. A detailed description of the success criteria and their sub-criteria can be found in [3].

3 Selection and Justification of Samples

In order to compare the project success of large underground construction projects in Germany and Switzerland, a project portfolio of large underground construction projects was compiled for both countries according to previously defined selection criteria. The entire project portfolio includes road and rail tunnels in Germany and Switzerland. The tunnels considered have a minimum length of 1.5 km, cumulatively over all tubes. Only new constructions with an investment volume of at least 100 million euros are examined. The construction of a new tube of an existing tunnel is considered as new construction. In addition, only tunnels that were commissioned in the period between 1980 and 2021 or that could have been expected to be commissioned are taken into account.

Based on the literature and the data freely available on the internet, 65 tunnels in Germany and 70 tunnels in Switzerland could be clearly assigned to the criteria. The projects for the respective samples for Germany and for Switzerland were selected from the project portfolio. Since only a limited amount of the data needed to classify the projects in the measurement system was freely available, most of the data was obtained through interviews with project participants using a questionnaire. The sample was therefore largely determined by the willingness of the project participants to be interviewed. The data from the 29 interviews conducted were supplemented by a literature and internet search as well as by raw data from another paper.

A total of 70 underground construction projects were considered and evaluated in this work [3]. This sample is composed of 45 Swiss and 25 German projects. The different sample sizes of the two countries result from a better data availability in Switzerland.

4 Basis for Comparison

The 70 underground construction projects considered were sorted into the measurement system and evaluated on the basis of the data obtained. For a better overall view, the individual success criteria were considered within the framework of [3] using mean values of the samples or sub-samples as a comparative measure. Individual projects were not examined in detail. The resulting mean project success for each success criterion is used to compare the German and Swiss samples. In order to enable a uniform basis for comparison, only underground construction projects with commissioning from 1999 onwards are taken into account for the overall comparison of the two countries, as it was not possible to obtain sufficient data for Germany on projects with commissioning before 1999 and Switzerland sometimes shows greater differences in the success criteria between the older and the newer tunnels (see also Fig. 4).

5 Comparison of Results Between
Germany and Switzerland

The overall comparison of the results determined for the project success of tunnelling projects in Germany and Switzerland shows that the German projects perform better, especially with regard to the success criterion “occupational safety” (Fig. 2). The difference in the mean target fulfilment levels of 1.2 is indeed significant and the largest for all success criteria. The comparison of the criteria “cost” and “schedule” shows that compliance with the planned costs and schedules works better in Switzerland. This can be explained primarily by the fact that in Germany it is often not possible to take provisions for risks and contingencies into account in the financial budget. However, since no underground construction is risk-free, systematic risk management is of great importance and an estimation of costs for the occurrence of potential risks in the financial budget is mandatory [5]. The mean target fulfilment levels for these two success criteria are 0.5 higher for the Swiss projects than for the German projects.

2 | Comparison of the project success in Germany and Switzerland
Credit/Quelle: Escherich

2 | Comparison of the project success in Germany and Switzerland
Credit/Quelle: Escherich

Germany and Switzerland show only slight differences in the average degree of target fulfilment for the criteria “quality”, “organisation and processes”, “environment” and “public opinion”. For “organisation and processes” (difference of 0.2) and “public opinion” (difference of 0.1), the Swiss projects examined have slightly better average degrees of target fulfilment. The German projects, on the other hand, show slightly better mean target fulfilment levels for the success criteria “quality” and “environment” (difference of 0.1 in each case). The difference between the two countries with regard to “organisation and processes” results primarily from better “partnership-based cooperation” in the Swiss projects. With regard to the success criterion “environment”, Switzerland shows better target fulfilment levels in the recycling of excavated material from the underground construction projects within the framework of the model considered. As Germany has a slightly better degree of target fulfilment for general environmental sustainability and both countries perform similarly with regard to compensation measures, the differences in the overall environmental assessment are largely balanced out. For the success criterion “public opinion”, Switzerland again achieves slightly better target fulfilment levels than Germany, which can be explained above all by a better timing and a higher degree of involvement of the population. However, the differences between Germany and Switzerland for the four success criteria mentioned are so small overall that no clear statement can be made as to whether one country is really more successful than the other here.

The results show that the target fulfilment level 2 (“reaching the target value”) is almost reached for some success criteria, but not completely reached or even exceeded for any country. Only in rare cases do projects have a target fulfilment level of “exceeding the target value” (3). All other target fulfilment levels (1 to -3) represent a negative deviation from the project requirements, so that the overall rating of the success criteria of a sample is typically lower than target fulfilment level 2.

In summary, it can be stated that with regard to the success criteria “cost”, “schedule” and “occupational safety” there are greater differences between the countries of Germany and Switzerland. On the other hand, both countries are similarly successful with regard to “quality”, “organisation and processes”, “environment” and “public opinion”.

From the comparison it can be deduced that in Switzerland there is a need to catch up with regard to occupational safety. This lack of progress has already been recognised in Switzerland and measures are being taken to improve occupational safety in Swiss underground construction projects. The results of this work show that these measures should be continued and intensified. For German underground construction projects, the comparison reveals a need for action with regard to the success criteria “cost” and “deadlines”. Here, for Germany, a consideration of risk costs including a provision for unknowns in the budget is necessary for an improvement of the status quo. In addition, project success can be increased if the recommendations for action of the reform commission “Construction of Major Projects” [5] are also consistently implemented in the realisation of major projects, as the samples of both countries show a strong influence of the partnership approach. This becomes evident by dividing the samples into projects with cooperative as well as confrontational cooperation (Fig. 3).

3 | Comparison of the achievement of objectives as a function of the manner of project cooperation
Credit/Quelle: Escherich

3 | Comparison of the achievement of objectives as a function of the manner of project cooperation
Credit/Quelle: Escherich

In conclusion, the comparison of the German and Swiss samples shows that despite the differences in the individual success criteria, no country is clearly more successful overall, as all success criteria must be considered in order to evaluate project success. Drawing conclusions about project success from the sole consideration of individual success criteria can lead to misinterpretations and is therefore not recommended.

6 Assessment of the Significance
of the Results

For a comprehensive assessment of the results of the direct comparison between Germany and Switzerland, they were analysed and discussed with regard to their significance and possible trends. For this purpose, a sensitivity analysis, a variance analysis and a correlation analysis were carried out.

6.1 Sensitivity Analysis

The sensitivity analysis was undertaken to determine how sensitively the evaluation of the success criteria reacts to the variation of the data input. For this purpose, it was assumed that 10 % of the underground construction projects in both samples were classified as 1 too positive or too negative with regard to the target fulfilment level of all success criteria. The sensitivity analysis shows that statements about general differences between Germany and Switzerland with regard to the success criteria “quality”, “organisation and processes”, “environment” and “public opinion” should be refrained from on the basis of the results of this work, since the small differences can also result from the subjectivity of the interview partners and a varying data basis. For these success criteria, both countries perform similarly well and no statement can be made as to whether one country is better. For the success criteria “cost”, “schedule” and “occupational safety”, however, a statement about differences between Germany and Switzerland is possible.

6.2 Variance Analysis

In a subsequent step, a univariate analysis of variance (ANOVA) was used to examine whether the differences between the two countries on the individual success criteria (referred to below as the “influence of the country”) are statistically significant. Furthermore, a multivariate analysis of variance (MANOVA) is used to analyse whether the country has a significant influence on the project success as a whole. In addition to the influence of the country (Germany/Switzerland), the influence of the tunnel type (road/rail tunnel) and the partnership approach (cooperative/confrontational cooperation) on the project success is also examined. The partnership approach in particular is an important success factor for large infrastructure projects.

From the results of the univariate analysis of variance for the individual success criteria, the conclusion can be drawn that the country only has a significant influence on occupational safety. In contrast, the differences in the other six success criteria are not significant. With regard to the type of tunnel, no significant influence is found for any success criterion, whereas the partnership approach has a significant influence on the success criteria “cost”, “schedule”, “organisation and processes” and “public opinion”. For these success criteria, the examined projects with cooperative collaboration show significantly
better mean target fulfilment levels than the examined projects with confrontational collaboration.

The MANOVA confirms the findings that the partnership approach has a major influence on project success and that cooperative collaboration should be strived for. In contrast, the influence of the country and the type of tunnel on the success of the project as a whole is assessed as low on the basis of the MANOVA. 

6.3 Correlation Analysis

In a final step, a correlation analysis was used to examine whether there is a connection between the success criteria and the time of commissioning of the underground construction projects. For both the success criteria “environment” and “quality”, there is a strong positive correlation with the time of commissioning. This result underlines an increasing awareness especially for the environment in the course of the last years. Another reason for the increased project success in terms of quality and environment could be a tightening of regulations and requirements as well as an advance in the state of technology, for example with regard to materials and machinery.

A final examination of the correlation between the partnership approach within a project (cooperative and confrontational cooperation) and the time of commissioning of the underground construction projects shows a slight trend towards confrontational cooperation (see Fig. 4). This trend towards confrontational cooperation should be criticised based on the results of the variance analysis. Care should be taken to ensure that this trend does not continue and, above all, does not intensify. Instead, it is recommended to promote stronger cooperative collaboration.

4 | Discernible trend towards more confrontation in Swiss underground construction projects (decrease in rating in the criterion „organisation and processes“)
Credit/Quelle: Escherich

4 | Discernible trend towards more confrontation in Swiss underground construction projects (decrease in rating in the criterion „organisation and processes“)
Credit/Quelle: Escherich

7 Summary and Outlook

In summary, it can be said that large underground construction projects in Switzerland are not fundamentally more successful than in Germany when all success criteria are equally considered. Although it can be seen that Swiss underground construction projects are more successful on average in meeting cost and deadline targets, Germany has higher target values on average with regard to occupational safety. The further investigations show the great influence of cooperation on project success, so that cooperative collaboration proves advantageous for projects in both countries in any event.

References/Literatur
[1] Handelsblatt GmbH, „Warum sind die Schweizer bei Großprojekten so viel besser?“, Handelsblatt, 2014. https://www.handelsblatt.com/technik/das-technologie-update/frageder-woche/deutschlands-baupannen-warum-sind-dieschweizer-bei-
grossprojekten-so-viel-besser/10039774.html (zugegriffen 27. Juli 2021)
[2] G. Hammerschmid, H. K. Anheier, und K. Wegrich, „Planung und Management öffentlicher Infrastruktur: auf dem Weg zu einer
besseren Governance“, 2016
[3] Escherich, Sophie: „Organisation von grossen Untertagebauprojekten in Deutschland und in der Schweiz – Eine Vergleichsbetrachtung zu den Erfolgskriterien“, Masterarbeit, Institut für Bau- und Infrastrukturmanagement, ETH Zürich, Zürich, 2021
[4] H. Ehrbar, „Notwendigkeit zur Etablierung von Risikomanagement-Prozessen in Großprojekten“,
Braunschweiger Baubetriebsseminar 2017, 2017
[5] Bundesministerium für Verkehr und digitale Infrastruktur, „Reformkommission Bau von Großprojekten – Endbericht“, Berlin, 2015
About the Author
Sophie Escherich was awarded first prize in the “Youth Forum” competition at the STUVA Conference 2021 for this contribution*. The contribution is based on her master's thesis from 2021 (Institute of Construction and Infrastructure Management, ETH Zürich). Sophie Escherich has been a project engineer at Gähler und Partner AG in Switzerland since 2021.
 * This first prize was awarded to two prize winners for the first time in 2021. The co-winner is Sebastian Kube, who received the award for his own presentation.


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