Conference Agenda

Continuous improvement programs are a cornerstone of operational excellence in manufacturing and logistics. Firms rely on structured idea management systems to channel employee suggestions for process improvements into tangible efficiency gains. Yet realizing the operational value of these ideas depends not only on selecting the right ones, but on doing so promptly. Delayed evaluations erode the value of approved improvements and, as research on procedural justice suggests, undermine the cooperative behavior of employees who perceive the process as slow or unfair. Despite this practical importance, prior research has focused almost exclusively on the outcome of idea evaluation — which ideas get selected — leaving the process largely unexplored. This paper asks: what factors drive idea evaluation time in operational improvement systems, and how can we explain their impact?

We draw on longitudinal data from the internal idea management system of a large European manufacturer in the mobility industry. The dataset covers more than 1.2 million evaluation activities from over 30,000 unique evaluators for roughly 240,000 submitted kaizen ideas spanning 14 years (2004–2018), with precise timestamps for each evaluation step. Ideas range from small operational upgrades (e.g., tool mounting improvements) to significant process changes (e.g., restructuring manufacturing workflows).

Given that theory on evaluation speed is nascent, we follow a two-stage approach. First, we apply algorithm-supported induction: we train a gradient boosting model (XGBoost) and use Shapley values (SHAP) to surface patterns in the data, which we then embed in existing theory to formulate hypotheses. Second, we test these hypotheses on a held-out sample using a two-way fixed-effects OLS regression.

Results reveal several robust drivers of evaluation time. Evaluations take roughly one-third longer when evaluator and ideator share the same organizational unit, pointing to coordination overhead or heightened local scrutiny. Involvement of higher-hierarchy evaluators in prior steps cuts evaluation time by around one-fifth, suggesting senior participation resolves operational ambiguity or raises process priority. A higher average duration of preceding activities increases the focal evaluation time — consistent with collective shirking — while longer prior-evaluator time reduces it, suggesting effort substitution. Evaluator workload increases delays; ideator experience and recent dual-role activity (having submitted an idea oneself) reduce them.

The findings offer actionable levers for operations managers seeking to accelerate improvement cycles, reduce procedural drag, and sustain employee engagement in continuous improvement programs.

Inland waterways offer a good opportunity to expand the inland traffic routes. Current standards involve transferring goods from seaports to the hinterland by road or rail. However, road transhipment is especially unreliable and depends on traffic. In addition, there are high emissions. Another way for inland transhipment is by train, which is often less well connected than road traffic, leading to a combined use of train and road traffic, with each depending on the other. A third possibility here is the usage of inland waterways. These are currently used sparsely, but have high potential to reduce road traffic and lower emissions. Especially in the context of container transhipment. Unfortunately, there is a lack of decentralised, conveniently located, transhipment points, which could reduce the last mile of container transport by truck and thus create incentives for the increased use of waterways.

This paper proposes a conceptual planning approach for decentralised transhipment points by leveraging small, modular facilities built into existing infrastructure, such as bridges. The installation of these so-called “MicroPorts” aims to lower the threshold for accessing inland waterway transport. The proposed approach supports the early planning phase of MicroPorts. First, potential locations are evaluated using suitability criteria, including available space, access to existing infrastructure, and local demand for container handling. Second, the required services of the MicroPorts are defined. These are core functions, such as container handling and temporary storage, as well as potential additional services, such as long-term storage or container repair. Then, the technical concept defines a basic layout including areas for transhipment, container handling, storage, and other services. Furthermore, the technical concepts define the required equipment for container handling and storage, e.g., mobile handling systems such as reach stackers or fixed solutions such as gantry cranes. Last, a discrete-event simulation should assess how an additional transhipment option affects container transport costs and emissions, for instance, in cases where customers currently relying on truck transport may shift to inland waterway transport.

The planning approach is illustrated through an exemplary use case on an existing inland waterway route, where a potential MicroPort site is identified. At the selected example location, existing infrastructure can be repurposed, reducing the need for investment. The simulation results indicate that using a MicroPort can lead to lower transport costs and emissions than truck-based container transport. While the approach supports conceptual planning and evaluation of decentralised transhipment points, further steps are required before realising the concept, including detailed cost assessment, construction planning, and administrative approval processes.

Introduction:
Port calls constitute a central component of global maritime logistics, as they influence vessel turnaround times, cargo handling efficiency, and the reliability of the overall supply chain. Despite international guidelines such as ITPCO (International Transport and Port Call Optimization), operational procedures vary considerably between ports. The aim of this study is to systematically analyse port call processes across selected representative ports in Africa, the Americas, Asia, Australia, and Europe in order to identify differences as well as potential areas for optimisation.

Methodology:
The present study examines port call processes through a comparative analysis of ten selected ports, comprising one small and one large port per continent: Durban and Casablanca in Africa, Los Angeles and Honolulu in the Americas, Shenzhen and Basuo in Asia, Melbourne and Broome in Australia, as well as Rotterdam and Aalborg in Europe. The analysis is based on publicly available information from the respective port websites and the specialist publication Guide to Port Entry. Five key aspects were investigated: port size, port call guidelines, the application of ITPCO-defined timestamps, communication structures, and operational coordination between involved stakeholders. Based on these analyses, a classification framework was developed to systematically capture similarities and differences between the ports. The methodology therefore combines a structured comparison of current practices with a critical evaluation in order to clearly structure the main aspects of port processes and identify optimisation potential.

Results:
The analysis demonstrates that the level of detail in process descriptions is heterogeneous, ranging from limited to highly detailed, thereby indicating considerable differences in the degree of standardisation of operational procedures across the examined ports. With regard to temporal process structures, the findings reveal only a partial implementation of standardised timestamps. While the Estimated Time of Arrival (ETA) is communicated consistently in all ports, other relevant timestamps, including process-related milestones, are recorded systematically only to a limited extent. In addition, the communication structures can predominantly be characterised as analogue to hybrid, as operational coordination is still largely conducted via VHF radio or telephone. Digital systems are generally employed only as supplementary tools, primarily in the preliminary stages of service booking and administrative coordination. Consequently, the overall level of operational coordination can largely be classified as low to moderate, as integrated and continuous coordination between all involved stakeholders is only partially achieved. Overall, the findings suggest that the incomplete standardisation of timestamps, combined with only partially digitalised and fragmented communication structures, reduces the predictability, transparency, and operational efficiency of port call processes.

Originality:
This study provides a cross-continental comparative analysis of port call processes, an area that has received only limited attention in the existing literature to date. In doing so, key aspects relevant to port calls are integrated within a unified analytical framework. On this basis, specific efficiency deficits can be identified, and potential avenues for process and operational optimisation can be derived. Overall, the study establishes a robust foundation for further research as well as for the development of approaches aimed at enhancing the efficiency of port call processes.