Purpose: The construction industry is responsible for great amounts of resource consumption, waste generation and both carbon and greenhouse gas emissions in the European Union. The currently still predominant linear mindset of take-make-consume-dispose must shift to reduce the industry’s environmental impact and enable the transition towards a circular construction industry. Circular material hubs facilitate more circularity by collecting, processing, and redistributing secondary building components to make them available for another life cycle. In literature, little can be found about the system circular material hubs are embedded in and their connection to architects. This study investigates the system of circular material hubs in the Netherlands, its challenges, opportunities, and potential future developments in the transition towards a circular construction industry. A special focus is placed on the role of architects within this system, as a circular construction industry also needs designers to include secondary building components in designs. The Netherlands is one of the top nations in the reuse of secondary raw materials and therefore provides as an exemplary setting for this exploratory research.
Methodology: An exploratory, qualitative research approach was chosen. Fourteen semi-structured interviews were conducted with representatives from circular material hubs, architects, as well as experts in the fields of circular economy, circular construction industry and construction logistics. Practitioner interviews aimed at identifying practices performed within the system of circular material hubs, and detecting challenges, opportunities and potential future developments as perceived by practitioners in the field. Expert interviews were conducted to validate the information gathered through literature review and practitioner interviews.
Findings: The research found four practice bundles which are important for the system of circular material hubs. These practice bundles are acquisition practice, processing practices, sales practices, and material harvesting practices. Within these practice bundles, different practices and performances of these practices were identified. The practices influence each other. Which building components are acquired influences which processing practices need to be performed. The type of building component also influences the sales practice as different building components target different groups of clients and are sold through different communication channels. It is also crucial whether the building components are sold offline or online. The online marketplace of Insert was found to be particularly helpful, as it is specifically designed for the construction industry and used by circular material hubs as well as architects. This shows the influence of the choice of communication channel on a circular design practice and scouting practices. By providing as much information as possible about the secondary building component at hand, circular material hubs also facilitate a circular design practice. Additionally, challenges, opportunities, and potential future developments of the system of circular material hubs were identified. Challenges the system faces are related to uncertainty and irregular assortment, guidelines, costs, and the provision of guarantees, while opportunities are governmental decisions, the provision of information and the use of shared online marketplaces. Missing collaborations are both a challenge and an opportunity. Future developments are primarily related to changes in the provision of secondary building components.
Research limitations: The limitations of this study are that social practice theory was not applied to the entire research as it is not suitable for the assessment of challenges, opportunities, and potential future developments. A greater variety of circular material hubs, not in number but in their field of activity, could present a different view on the system. Semi-structured interviews also always have certain limitations. Identifying the practices while they are being performed could also have led to more in-depth results.
Originality/value: By providing a comprehensive view on the system of circular material hubs in the Netherlands, this research helps to understand the dynamics within the system and allows the identification of potential interventions based on the practices that constitute the system.

Quay cranes on modern container terminals have the possibility to lift two 40ft. containers side by side. In order to be able to perform this type of lift, the crane must be equipped with a tandem spreader. As this type of spreader cannot be used for performing certain lifts, such as the handling of hatch covers, switches between single spreader and tandem spreader are inevitable. However, there is no method in current literature nor in practice to determine when the spreader changes should be performed. Therefore, the aim of this research is to develop a model that calculates the optimal moments to switch spreaders. As the performance of tandem lifting depends on the cycle times, a cycle time prediction model is developed first. This Artificial Neural Network model predicts the cycle time based on the type of lift, the actual position of the container(s) on the ship, the weight of the load and the current wind speed. The predictions yield a Mean Absolute Percentage Error of less than 11%. Afterwards, the cycle time prediction model is used to develop an optimal spreader switching strategy model in the form of a Mixed Integer Linear Programming model. A case study, in which several different bay layouts of a container ship need to be handled, shows a decrease in handling time of up to 22% compared to the traditional spreader switching strategy.

Abstract
Purpose - The aim of this paper is to propose a method for performance measurement of the livestock feed industry from an environmental and economic perspective. There is a knowledge gap both in the literature and society in the field of performance measurement of the livestock feed industry with environmental concerns. Livestock feed companies need support in the decision-making process to produce environmentally sustainable livestock feed at as low as possible costs.
Design/methodology/approach – An environmental performance index for livestock feed is constructed based on techniques of the min-max transformation, the analytic hierarchy process and simple additive weighting. The verified environmental performance index for livestock feed is brought into practice; different scenarios, which all represent a feed composition, are quantitatively compared to a benchmark feed composition. The environmental performance index is validated with an uncertainty analysis and sensitivity analysis.
Findings – The constructed environmental performance index for livestock feed is assessed by comparing nine scenarios against a benchmark feed composition. The results indicate that the environmental performance index for the livestock feed industry is technically feasible and effective to measure the performance of the livestock feed industry from an environmental and economic perspective.
Research implications – The constructed environmental performance index for
livestock feed can serve as a decision-making tool for livestock feed companies. As a response to climate regulations and a market pull, this paper provides a tool for livestock feed companies to select livestock feed compositions with the best performance based on environmental sustainability and economic performance.
Originality/value – A new performance measurement method is designed for an
environmental performance index for the livestock feed industry. From the literature, environmental sustainability variables are identified. The data on the environmental performance are obtained from a public database as well as a livestock feed company. The created index can contribute to decision-making in the livestock feed industry.

Social and political pressure has made emissions an increasingly important subject for companies. The extension of the sustainability reporting mandate by the EU has increased the necessity for carbon transparency for companies in Europe. Warehousing and distribution account for 13\% global supply chain emissions and can be an important factor in reducing company emissions. The traditional trade off in warehousing storage systems between cost, service level and emissions has mostly been in favor of cost and service level. Now however, emissions are becoming just as important to companies. This paper investigates the emission levels of manual and automated storage system, specified to aviation standard parts. Aviation standard parts are chosen as these are commonly stored using automated systems, due to the high degree of accuracy needed and the quantities involved in this sector. Current knowledge does not provide insight into the environmental footprint of automated and manual storage systems for small parts. This paper aims to fill this gap by combining literature research and expert consulting to gain insight into the carbon footprint of storage systems and modelling to gain insight into operational energy consumption. Finally, a case study is performed at an aviation parts dealer for empirical evidence on storage system emissions.

In this day and age sustainability is becoming increasingly important. Even though the airline business is not the first thing which comes to mind when regarding sustainability there are huge efforts in play to extend the life of airplanes and its corresponding components. This is done via remanufacturing. Remanufacturing can here be defined as:” Returning a used product to at least its original performance with a warranty that is equivalent to or better than that of the newly manufactured product” (Gunasekara, et al., 2018). Even though numerous attempts using traditional techniques like Lean have been tried at KLM E&M, none have yielded the long term desired results, which is why a different approach is needed. Remanufacturing brings numerous problems with it, unknown to traditional manufacturing (Guide Jr & Daniel, 2000). These problems result in the operational level of the organisation not having control over the process, which leads to subpar performances. Furthermore, a gap originates between higher level management and the operations, which leaves a lot of potential uncovered as well as discourage operational level progress. The proposed model is designed to help gain control over an uncontrolled process, improve its performance and sustain the newly found control, which is also the purpose of this research. This is all achieved using a more bottom-up integral approach. This proposed model is combined with the operational lean maturity model developed by Maasouman (Maasouman, 2015), in order to create a Remanufacturing Process maturity model, which indicates the maturity level of each aspect used in the Remanufacturing Process control model, resulting in a model which has both quantitative and qualitative aspects.

With the increasing focus on project planning in engineer-to-order(ETO) companies, tracking the progress of the design phase of a project is essential for effective planning. Such progress tracking currently is done through the regular feedback of discipline leads, which are intrinsically subjective. The information thus collected is then plotted in the form of so-called S-curves, to represent the progress over the course of the project. The present method tracks progress of the manufacturing engineering phase based on how much mass is designed with respect to the design weight of the equipment. This so-called mass curves are used and fitted to an S-curve and represent the tracked progress. It is shown that the fitted mass curves represent the progress of the engineering phase with a systematic average error of 25 days. Additionally, mass data retrieved from completed projects are used to predict the S-curves shape of the ongoing project. The weighted average of tracked and Predicted S-curves is then used in a Monte Carlo simulation in order to estimate the progress of the ongoing project. The method was found to have a tracking accuracy of 0:6 4%, which translates into an uncertainty on the project duration and therefore on the equipment delivery date, by 2 weeks. This uncertainty is found to be the upper bound of typical grace periods agreed with most clients. The present results might offer a new outlook on progress tracking on the progress tracking of manufacturing engineering activities. Further research shall be conducted to address the progress of earlier engineering phases equally.

Prysmian Netherlands as a cable producer uses a cable drum to deliver products to their customers. However, these customers do not always participate in returning this returnable packaging material (RPM). Customer willingness and reverse supply chain (RSC) visibility are mentioned as the main contributors. The study aims to develop improvement strategies and assess their impacts through a discrete event simulation (DES). The strategies consider the approach from logistics system design, technological implementation, and compliance policy. The findings suggest that an RPM with a high product residual value such as drums promises a high financial return if recovered. However, maintaining the returned drum condition is of the utmost importance to ensure the recovery operations are fruitful. Moreover, a shorter RL cycle time does have a substantial effect on the RSC efficiency.

This study aims to develop a decision support tool which enables shipowners to select the most appropriate alternative fuel technology to comply with possible different imposed emission regulations while ensuring optimal business performance. In this context, most appropriate is defined as a fuel alternative which minimises required freight rate (RFR) while maximising overall performance on technological, environmental and other criteria. A decision support tool was devised combining a decision model based on the simple multi-attribute rating technique (SMART) with a financial model based on discounted cash-flow (DCF). Additionally, an optimisation model was implemented to optimise for minimal required freight rate through slow steaming. The decision tool provides shipowners with a quantified impact on their current business if they do not transition to alternative fuels under a 'market based measure' (MBM) regulatory scenario, as well as best-alternatives if their current fuels do not meet regulations under an 'emission cap' (EC) scenario. The decision tool is evaluated under optimistic, average and pessimistic scenarios in 2020, 2030 and 2050. Under an emission cap scenario, the results showed an overall preference for Fischer-Tropsch diesel (FTD) as the most promising alternative maritime fuel both in terms of SMART performance and required freight rate, followed by upgraded bio-oil (UBO). Nevertheless, the average difference in required freight rate of alternative fuels compared to HFO remains substantial, at 43% and 38% higher for Fischer-Tropsch diesel under a 'no regulation' scenario and 'market based measures' scenario, respectively. It is therefore evident that without regulatory intervention, heavy fuel oil is expected to retain dominance based on cost. Even under a market based measure (MBM) scenario, the average required freight rate of HFO increases only by 3.4% overall. For LNG, market-based measures lead to an average increase in RFR of 4.1%. These results suggest that in order for the maritime industry to transition towards sustainable alternative fuels, policymakers, governments, international organisations and lenders need to align their policies to collectively enable a more sustainable shipping industry - not only by enforcing stricter regulations, but also by providing the correct financial incentives.

This research focuses on identifying and evaluating ways to improve the sustainability of solid waste management (SWM) in semi-public spaces using the Efteling theme park as a case study. To the best of the author’s knowledge, this study is the first to apply an integrated waste management approach to optimize SWM in this context. The approach consists of assessing the integrated environmental and economic burdens of the collection, transportation, sorting and treatment processes of a SWMstrategy. Approximately 10 alternative high potential SWM strategies were composed and selected out of a very large pool of possible SWM strategies. The environmental and economic impact of these high potential SWM strategies for the Efteling case was subsequently assessed using the WARM LCA model and a custom economic assessment model. The results reveal that emission reductions of up to 190 ton CO2 equivalents (TCO2E’s) per year, relative to the current strategy, can already be achieved by separating and recycling more fractions from behind-the-scenes (BTS) waste. This corresponds to an increase in yearly avoided SWM system emissions of about 25% for the Efteling case (from a life-cycle perspective). When public/semi-public (PSP) waste is also included, emission reductions of up to 800 TCO2E’s per year can be achieved for single-fraction separation (e.g. PMD or PET) and up to 960 TCO2E’s per year for two-fraction separation (e.g. PMD + paper or PMD + cups). This corresponds to major increases in avoided SWM system emissions of 110% and 131% respectively. It was also found that small interventions in the transport and/or treatment waste management components can make a big difference in the environmental and/or economic impact of a SWM strategy. A majority of the alternative SWM strategies has an eco-efficiency (emission reduction cost-effectiveness) ranging from €39 to about €140 per TCO2E saving. This eco-efficiency is (much) higher than that of a range of benchmarks such as the eco-efficiency of solar-pv panels at a non-industrial scale, wind turbines at sea and the eco-efficiency of office building insulation. This indicates that optimizing waste management should be given more priority in (scientific) research as well as in practice.

The continuing growth in air travel passengers, in combination with enhanced security regulations, has led to unsustainable situations at airports. In order to handle the future amount of air travel passengers while complying to security regulations and enhancing the passenger experience, the terminal system must be innovated. Seamless flow is a future end-to-end continuous, efficient and secure innovation which uses passenger biometrics for identification throughout the airport processes. Previous research is focused on fitting the new seamless flow technology in with the conventional airport processes. This research explores whether the biometric technology could lead to new, and feasible, passenger terminal concepts. Two new seamless flow concepts are constructed and assessed on their feasibility by conducting interviews with stakeholders, performing desk-research and executing a financial Cost-Benefit Analysis. The research findings indicate that the new technology could lead to feasible, efficient and experience enhancing passenger terminal concepts in comparison to the conventional terminal concept equipped with seamless flow technology. Thereby, the support of - and collaboration between - stakeholders, especially the border guard agency, is shown to be essential for the implementation of seamless flow technology on civil airports. Besides that, it is shown that more efficient terminal concepts could significantly benefit airports through increased commercial opportunities.

Convention centers are facing logistic challenges due to poor performance, lack of space and governmental regulations. This research is focused on finding strategies that can improve performance while maintaining or reducing space and complying to these governmental regulations. In this research three main strategies are introduced that can improve logistic performance at convention
centers. These main strategies are: a truck appointment system, extended operational times and cross-docking. Besides these strategies specific designs are made for the case of the RAI Amsterdam. These designs differ in infrastructure and material handling equipment such as automated vehicles. It was found that implementation of a truck appointment system, extended operational times and cross-docking can improve the performance of convention center logistics. Further improvements can be made by adjusting the infrastructure and by the use of automated vehicles.

Planning the on-site transportation of large manufacturing sites is a complex process. Currently these plans are made based on the on-site logistics constraints rather than on KPIs. Research has been focused on either analysis of system parameters or generally on KPIs, but lacks the combination of both on real-life cases. This gap is closed by taking both system analysis and KPI development into account to develop a working planning tool that can assist planners in a real-life situation. The goal of this study is to gain insights in the on-site transportation planning of large manufacturing plants and their performance measurement. This study answers the question: How can the on-site transportation planning at a large manufacturing plant be improved, by 1.) adding company KPIs and 2.) data-driven decision support based on the parameters of the locality and its constraints? Through the application of the DMADE methodology, this research question is answered. The SCOR performance measurement framework is used to determine the KPIs of the on-site transportation plans. A planning model, classified as a Resource-Constrained Multi-Project Scheduling problem, is formulated as a Mixed-Integer Linear Program. This planning model optimizes the on-site transportation plans for the KPIs, proves the correctness of the KPIs and shows the potential performance increase of on-site transportation plans if constructed by the planning model.

Due to the global climate change there is a increasing demand for transportation on renewable fuels. An increasing trend in electric propulsion can already be seen in the automotive industry and this is now also gaining popularity in the maritime sector. Due to limited capacity if the onboard battery, especially electric ferries are becoming more popular, because of the relative short sailing distances. The first electric ferry became operational in 2015 in Norway and since than a hand full of electric vessels was developed. An electric vessel requires a charging mechanism to charge while unloading and loading passengers in the port. Besides, generally also a mooring mechanism is necessary. This enables the vessel to turn off the propeller while charging which limits the energy demand while charging. Various systems have been developed already. However, these are not standardized solutions but all one of a kind systems designed for a specific vessel or fleet. Which of these is the best solution is not easy to determine and strongly depends on the vessel characteristics and the operating environment. To supply the expected increasing demand for electric vessels, a guideline is developed which will help the engineer to find a suitable charging and mooring mechanism and to decrease the selection time for this system. The will provide Damen a strategic advantage towards other shipyards in vessel tenders since both the development costs and delivery time is lower.
This guideline is developed based on the knowledge gained during a case study for a 81m Ropax ferry, sailing in the surroundings of Vancouver Island. For the case study an engineering design method was selected from literature and applied to this case, for which Damen had a hard time finding a charging and mooring mechanism. First thought was to combine both into one mechanism, but this is difficult due to conflicting functionalities of both systems. Due to the limited time available for the research, the design of the mooring mechanism is not taken into account for the case study. Setting the requirements for the charging mechanism is complex due to the range of different fields of interest that should be taken into account. However, the requirements of these various aspects are often related in some way to one another. This makes it easy to lose sight of the structure of all requirements. Comparing the functions that the charging mechanism should fulfill within these requirements and the existing charging mechanisms, it can be concluded that no suitable system is available yet. The gap between these is defined as a set of three functions; to compensate the tidal difference, deal with misalignments between the vessel and the shore and to provide flexibility for vessel motions. A new design was made which covers this gap. Additional research was done to ensure sufficient flexibility from the power cable, since this proved to be critical in the state of the art systems.
From the knowledge gained during this case study, the guideline is developed. The guideline provides insight in the influential factors while selecting an mechanism. This should offer the engineer a structure to set the requirements and ensures that no aspect is left out of the requirements. An overview with the already existing mechanisms is provided which should be consulted multiple times during the process, to check whether a suitable systems exist, if the requirements should are too tight or if the project is not profitable at all. The structure of the requirements is designed such, that the relative easy requirements are set first. This prevents from doing demanding calculations or going on expensive business trips, while it could have been seen earlier that a project is not feasible or profitable at least. The guideline is validated while selecting a charging mechanism for a different type of vessel. This validation proved to decrease the selection time for a charging mechanism significantly compared to previous projects within Damen. After the test, a charging system was found which is preferred for the vessel. This charger is now further discussed with the supplier of the system.

In the construction industry, it is common to predict manufacturing times of structural elements based on the experience of shop managers. With the increasing use of Building Information Models (BIM) and data analysis in manufacturing processes an opportunity for improving the accuracy of predicted manufacturing times arises. This research proposes a general prediction model based on physical properties of structural elements extracted from BIM, along with manufacturing times of manufactured elements. The proposed Support Vector Regression Model Tree (SVRMT) is tested in both hypothetical and real case scenarios. Through validation in real case scenarios, the SVRMT prediction model turned out to be a significant improvement in terms of prediction accuracy, compared to the current experience based approach.

Diesel-powered Automated Guided Vehicles (AGV) are currently deployed for container transport at terminal’s water side. Looking at the trends in formal legislation and market developments towards sustainability, these diesel AGVs are most likely to become outdated. Although battery-electric AGVs are an emerging, zero-emission alternative, there are serious technical, operational and financial questions regarding their implementation at brownfield terminals operating 24/7. Taking the northern side of the ECT Delta Terminal in the port of Rotterdam as a case, the operational and financial feasibility of replacing diesel AGVs by a battery-electric AGV fleet have been evaluated by means of a functional design of the AGV charging process, simulation study and total costs of ownership analysis. The results indicate that battery-electric AGVs opportunity plug-in charged at the automated stacking cranes’ transfer points prove to be an operationally and financially feasible alternative to diesel AGVs: operationally under the condition that a sufficient amount of AGVs, charging power and plug-in chargers are installed and financially under the condition that the increasing trend in diesel price and decreasing trend in electricity price will continue in the near future. As environmental legislation for heavy-duty vehicles becomes more stringent while there is a decreasing trend in electricity prices, battery-electric AGVs are most likely to become profitable for deployment at brownfield container terminals. Therefore, this study’s findings could pave the way for terminal operators to replace their environmentally unfriendly diesel AGVs by zero-emission vehicles, potentially becoming the key force increasing the global penetration rate of electric vehicles in heavy-duty industry.

The introduction of MARS stands at Amsterdam Airport Schiphol’s new A-pier means a Clean VOP policy will be enforced. Under this regulation, vacant aircraft stands must be free of any cargo and baggage. In order to comply with this policy, KLM Cargo has to redesign its cargo handling procedure which is currently based on push logic. This paper explores the effects of various cargo handling procedures using pull and push-pull logic on KPIs such as on-time performance, space usage and distance covered. These handling strategies are simulated using a DES model of the future A-pier. The resulting KPI values are then analysed using the analytical hierarchy process, where weights are assigned to the KPIs by the problem owner. The resulting weighted scores indicate that a strategy employing a combination of a pull and push system is found to be most effective at ensuring cargo is delivered on time while respecting the Clean VOP regulations imposed by the airport authority.

A traceability system for primary packaging materials is compulsory by law for the food- and beverage industry. With a good traceability system an organisation is able to quickly recall unsafe products to protect consumers health. This research aims to analyse and improve the traceability of the primary packaging materials at Heineken Netherlands. A second focus of this paper is to reduce the impact of a potential recall on packaging materials. This research is performed based on the method called the five-stage-of-a-prescriptive-model. Using this model results in a step-wise development of an improved design. A literature study, a problem analysis and the customer requirements will be the input of this design. Analysing the current traceability systems showed traceability issues as unregistered in- and outgoing flows of packaging materials at pallet level and registration issues as double scanning. Another issue that is observed is lot segregation at different breweries, at different production lines and on different production dates. The lot segregation will cause that in times of a recall an organisation has to withdraw significantly more products. Using a Multi Criteria Analysis and the Ease and effect method results in a final design based on organisational changes, periodic evaluations, barcode technology and RFID technology. Implementing this design guarantees the traceability since all the incoming and outgoing flows are registered at pallet level and the registered data is periodically evaluated. By procedure adjustments at the supplier and at Heineken also results that the impact of the recall volume can be reduced.

A promising vision to make the global logistics more sustainable is 'Physical Internet Logistics'. This vision, based on the way 'Digital Internet' sends packages information through a network, is focused on optimisation of handling, storing, realising and supplying objects. Physical Internet Logistics suggests an open, global and interconnected network with different spokes, hubs and modes. Objects are encapsulated in standardised containers whereafter they will be distributed through a network. Routing of the container is focused on network balancing. Every container will follow its own path through the network from origin to destination by using different hubs. Different origin-destination pairs will be bundled and transported on the same link. Besides, similar origin-destination pairs could follow different paths through the network. At hubs, transhipment takes place to transfer containers to different routes. This paper is focused on the application of Physical Internet characteristics in the parcel delivery industry using an optimisation model concerning fleet allocation on a service network. The objective is to find such a fleet allocation plan in which the total amount of emitted CO2 is minimised. Two different designs are suggested: a 'hub design' and an 'open network design'. For the hub network design, a couple of nodes are defined as hub where transhipment can take place. Paths from origin to destination are only possible by using at least one hub. This means that demand travels from origin to hub to destination. For the Open network design, transhipment is possible at every node. Paths from origin to destination are possible in one direct way or by using a hub. This means that two kinds of paths are possible, from origin to destination or from origin to hub to destination. By using a case study at PostNL, a carrier in the Dutch parcel delivery industry, this paper concludes that the application of Physical Internet characteristics do have its influence. In particular, the openness of a network result in a reduction in total amount of emitted CO2. During the case study at PostNL, it became clear that a CO2 reduction of 6% is possible when the elements of Physical Internet were applied on a hub network design. The open network design is able to reduce the total amount of emitted CO2 by 16%. When the demand is known by forehand this paper concludes that a less restricted network results in less CO2 emissions emitted. Destinations should be severed by more than one hub or directly by the origin depot. Transhipment should be possible at as much as nodes as possible. Concerning a case in the parcel delivery industry, it is hard to make forecasting more reliable on a daily base due to the short time windows of delivery. This means that a carrier as PostNL should innovate in the flow of information from shippers to make the application of Physical Internet feasible.

Due to complex nature of aircraft heavy maintenance checks, achieving process stability is difficult. Literature suggests that this stability can be obtained by separating routine and non-routine work, and focusing on quick identification of non-routine tasks by completing inspection tasks early in the check. Current task planning methods show limitations in producing a feasible task planning, motivating the need for an advanced task planning model. This model combines the task elements of manpower, work order, and aircraft zone to find the minimum TAT given the task complexity-based heuristic. For this model, aircraft zones have been redefined, as the zones specified by Boeing are not suitable for task planning. An experiment using the advanced task planning model is conducted for the Inspection Phase tasks of the Boeing 777 C07 check. The target is to complete all tasks in 48 hours. Results show that it is feasible to perform all Inspection Phase tasks in 61.28 hours, where 99.51% of the tasks is completed in 48 hours. Completing all tasks takes 8 shifts, with a maximum of 31 technicians in a shift. The total TAT can be further reduced by identifying and lifting the constraints in the planning. One example shows how this can lead to an 8 hour reduction in total TAT for the best experiment scenario, bringing the TAT closer to the 48-hour goal. This demonstrates how the advanced task planning method can be used to stabilise aircraft heavy maintenance.

This thesis addresses a problem at KLM E&M, where a gap exist between the desired performance and current performance of airframe MRO. This research is performed to find solutions within the A-check for wide body aircraft by identifying the constraint in the A-check and subsequently develop solution alternatives by first exploiting the constraint, then elevating and finally develop a ‘desired world’ alternative. For the A-check a theoretical preliminary model was developed which tests Phase-Gate methodology and concentrating resources within the phases during the check. It was found that applying Phase-Gate and aligning the available manpower to the workload could improve the output performance of the A-check. The best of the designed solution alternatives all consists an implementation of a core shift, which focus of aligning and full concentration of available manpower to the workload.