Keywords

1 Introduction

Within the conventional academic education, which includes lectures and additional tutorials, potentials regarding discussions and the personal development of the students are not fully exploited. In order to communicate the topic of product development in this context with a focus on sustainable and future-oriented products, creative ideas, approaches and impulses by the young engineers are an important input. As part of a semester-long project, the Project-Based Learning (PBL) is to supplement the traditional learning concept based on lectures and tutorials for developing such creative ideas. The approach of PBL allows the creation of an environment in which students can both, exercise their creativity to solve technical problems independently as well as reflecting their own leadership and communication behavior within a group.

Although the related module introduces models and methods of the ecological and economic dimension, the design project focuses only on the ecological dimension of sustainability. This restriction is primarily due to the structure of the current curriculum, since although economic and social-ethical practical modules are offered. Therefore the need for a new project concerning the ecological-technical intersection is there.

Many curricula already request that their students have to deal with topics like requirements for systems and products from the economic, environmental, social, political, ethical, health and safety, manufacturability, and sustainability area [1]. This increasing call for sustainability aspects within university teaching can be explained on the one hand by the communicated goals of the government and industry as well as on the other hand by the internal university goal to integrate students early within their degree program in presence Following semesters of online learning due to the pandemic [2].

In terms of the communicated goals, for example, the Sustainable Development Goals (SDGs) may serve as a basis for moving within engineering from optional sustainable system extensions to modifications which are required to meet these goals in the future [3]. To understand how these modifications can be made, not only conventional engineering modules are needed, but rather impulses on how interdisciplinary content can be used in a supportive manner [4]. Perpignan et al. (2020) published a tabular overview of interdisciplinary and conventional engineering competencies based on interviews [4].

Table 1. Cross and engineers skills (cf. [5])
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Within the scope of this new project, which will accompany the lecture, the aim is to develop an impulse-giving addition. In this module, interdisciplinary competencies (cf. Table 1) are to be imparted to the students through the application of project-based learning, and the sustainability of everyday products is to be examined using a concrete example. In contrast to the analysis of large systems, such as the analysis of the sustainability of the entire university activity [5], a more intensive discussion of the topic is to be achieved in smaller groups by analysing smaller systems (cf. [6]).

2 Project-Based Learning (PBL)

The Project-Based Learning (PBL) approach is a teaching method that focuses on the independent realization of projects to deal with issues within groups [7, 8]. Its objective is to make these groups address a complex issue over a predefined period of time, days, weeks or months, in order to both practice their existing competencies as well as expand their individual knowledge.

In order to satisfy the project nature of this approach, Thomas (2000) identified five basic characteristics of projects: Centrality, Focused Issue, Constructive Proceeding, Independence, as well as Realism [9, 10]. To implement these characteristics of a project in a teaching context, additional specific elements might be derived for student PBL [9,10,11]:

  • Time and self management;

  • Use of technological tools;

  • Optimization of group-internal information management;

  • Communication in groups;

  • Independent project management.

The PBL can be divided into three overarching fields in which each of these elements are applied - the cognitive, the content, and the collaborative learning [11]. First, the cognitive learning outlines the issue being investigated or the way of organizing projects and associated groups adapted to these issues [10,11,12]. Consequently, each group has to deal individually with the overarching problem as well as the tasks and challenges associated with it [11].

In contrast, the content area includes the engagement in form of interdisciplinary learning and as such the application of theories or methods to concrete practical challenges [11, 12]. Finally, the third area of collaberative learning includes the social aspects and the relevance of goal-oriented communication within groups [10, 11].

3 Case Study: Design Project “Sustainable Products”

As part of the present trend of sustainability efforts, the Faculty of Mechanical Engineering at Leibniz University Hannover is offering a new bachelors degree program "Sustainable Engineering" to enable young engineers to extend the range of conventional technical approaches. The Institute of Product Development has created a new course "Development of Sustainable Products" within the area of product development. Alongside the lecture and the tutorials, students are offered a semester-long design project.

3.1 Structure and Content

4 Aims and Concept

Furthermore, the students' learning potentials, especially the collaborative learning part, are to be increased by the PBL approach in the context of a concrete method, in this case life cycle assessment (LCA) according to ISO standard 14040 ff. Within this framework of LCA, the development of consciously ecologically sustainable products is pursued as an interdisciplinary component.

To be able to realize such an application in the project context, all product life cycle phases must be considered and examined in a holistic form. In addition, the students should acquire competencies in the use of sustainability accounting software through collegial learning and jointly identify potentials of sustainability for the product under investigation.

Tasks/Module

The structure of this design project is based on the general framework of the ISO 14040ff. Series of standards [13] and is divided into three task modules according to the phases of “Goal and Scope”, “Life Cycle Inventory” and “Life Cycle Impact Assessment” as well as a final presentation to demonstrate the “Interpretation” phase [14]. According to Fig. 1, each phase of the LCA can be attributed to the students’ activities, which are based on one another to enable the preparation of an entire LCA. Furthermore, within the total of seven activities, collaborative learning potentials have been identified, which are to be specifically leveraged through the students’ project work. These potentials are marked by exclamation marks in Fig. 1.

Fig. 1.
figure 1

Activities in the developed design project according to the phases of the life cycle assessment of ISO 14040ff. (cf. [13])

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Regarding the content the first work package addresses the first and second phase of the LCA of defining the objective and the scope of the study and establishing the life cycle inventory. In this work package, students should identify the product architecture of the object of study and establish its process chain. An example of a collaborative part within the activities is the development of the products architecture during the first phase of the LCA, the "Goal and Scope". In this activity, the students collectively investigate the demonstrator, disassemble all its components and, through internal group discussion, capture the functional as well as the product structure for the specific product example of an electric toothbrush. By combining the hands-on disassembly work and the theoretical formulation of the functional structure, the information can be linked and product-specific knowledge can emerge in the group.

During the second collaborative activity, the students shall independently investigate the life cycle inventories for the eight investigated components of the demonstrator and combine the results in a holistic model: the case, the electric motor, the electroacoustic transducer, the Printed Circuit Board (PCB), the lithium-ion battery, the charger, the travel case as well as the brush heads. As a result, the component-specific Petri nets are to be set up and modeled in Sustainability assessment tool (Umberto LCA+), with the inputs and outputs formed as a Life Cycle Inventory.

Subsequently, the students calculate the impact assessment for only one method and three impact assessment categories in order to limit the scope of the project work to a semester-compatible level. The results of these calculations are analyzed and interpreted regarding the identified results and summarized in a final, groupinternal prepared presentation.

4.1 Project Results

On the basis of these seven activities, the students combined their results in a final overall presentation. Two of the already mentioned main results with high collaborative potential are presented in the following section.

Product Architecture

In order to be able to make a statement about the structure of the product investigated, which is in this case an electric toothbrush, the students disassembled their demonstrator into all its components. This process was documented via photos, among other tools, to make it visually clear how the division of tasks (practical work and documentation of information) was organized as efficiently as possible within the group. Through collaborative communication between the students, the resulting product architecture includes information on further product models and/or product specifications (other manufacturers, additional functions,…).

Process Chains as Petri Nets

Following the disassembly of the products into their components and the set-up of the product architecture, the students have prepared the process chains for the individual components within the “cradle-to-cradle” process as preparation for the life cycle inventories. The students already got to know the relevant method in the accompanying lecture as well as during the tutorial, enabling them to apply and deepen this method within their group. According to the individual needs of the group members, the students can complement each other in terms of content and collectively model the process chain of the entire product concerning all components identified in the product architecture before.

4.2 Feedback

Measuring the success of the newly developed project is based, on the one hand, on the fluctuation within the semester and, the ratio between the number of registrations and the number of exams. On the other hand, anonymous as well as face-to-face feedback sessions were offered to the students and then evaluated at the end of the semester.

Since 95% of the registered students submitted a final presentation in the semester considered, there is a high level of interest by the students visible during this first iteration. In addition, the evaluation of the content and organization of the design project was positive. Another repeated aspect mentioned by the students refers to the possibility of holding a final presentation as a student group. These feedbacks support the advantages of project-based learning for strengthening not only leverage effects in terms of content, but also social integration in group structures.

The students' feedback after completing the course supports the previously made statements about the effects of the last online semesters. On the one hand, the possibility of working together in a group of students throughout the entire semester was positively noted, as this professional and private exchange provided a considerable additional value. On the other hand, the expected high degree of independence, especially regarding the autonomous calculation of LCAs, was perceived as partly overstraining, since the actual procedure within the framework of the applicable standards was left to the students and was not restricted by the lecturer. In sum, the overall project was recommended by the students for the coming iterations, allowing further adjustments to be made in the area of formulating assignments and guidelines to meet the students requirements.

5 Conclusions and Outlook

Within the scope of the student design project conducted, the various fields of project-based learning were applied and consciously promoted by the developed project concept. The cognitive as well as the content-related and collaborative components could be integrated in this project in a targeted way.

Cognitive and Content Learning

Regarding the potential cognitive and content-related benefits of PBL, various pros and cons of the design project can be identified. On the one hand, the development and implementation of the project enabled the students to investigate and apply new, previously unknown approaches within a classical engineering discipline. In addition, the students independently organized themselves as a group throughout the semester and consequently learned additional soft skills as well as implemented them via project plans, etc. Considering the content, both the students' use of previously unknown technical tools and the group's internal data management have been investigated. The several Petri nets created and resulting LCIAs calculated have been modified according their functional units and the level of detail considered. This enabled the students to implement a component-specific division of the tasks, to reduce the necessary processing times and thus to present their results in the form of a coherent final presentation.

Collaborative Learning

As the focus within this project, was on the exploitation of the collaborative potentials within project-based group work, the first iteration and the results generated can be considered to be positive. The continuous work on activities, of which only half had a collaborative component, enabled the students to build up a comfortable and at the same time creative working atmosphere, which resulted in new impulses for the development of sustainable products to be pursued further in future projects. For the specific example of electric toothbrushes, these were, for instance, the development of manufacturer-independent standardized charging stations or the reduction of the brush head volume to be exchanged in order to only replace the brush fibers in a modular way. These projects help students to learn to work independently, which in turn leads to a noticeable increase in interest in the topics to be taught, providing a high level of added value for all participants.

Based on the feedback of the students, the subject-specific material, e.g. guidelines for the usage of sustainability accounting tools, will be further developed in the coming semesters in order to be able to offer the students information appropriate to their needs. Furthermore, the aim should be to maintain the students’ knowledge throughout the projects to be able keep a kind of “project knowledge” regarding the development of sustainable products.

In addition to optimizing the design project for students, further events are planned by the institute to raise awareness among groups in the university environment. As an example, students of the region of Hanover will be offered a free supervision program during the summer vacations in form of a summer school. In this case, the aim is not only to convey the content as effectively as possible, but rather gain access to potential young engineers in a relaxed and enjoyable way and for raising their awareness.

Regarding future iterations of the project, it has become evident that the increase of interdisciplinarity in terms of the student composition as well as the aspects to be dealt with improves the communicability of the topic to be addressed. Although the ecological dimension and assessment of the technical systems will remain the focus of the project, ethical and economic implications cannot be neglected.