As the number of product variants continues to grow, the need for flexibility in intralogistics is becoming increasingly apparent. One potential solution to this challenge is the use of cellular automated guided vehicles, which can be variably interconnected depending on the size of the product to be transported. This article presents an optimization model for solving a vehicle routing problem for cellular automated guided vehicles. Furthermore, a recursive method is presented that determines an optimal transport sequence based on the solution of the model. The optimization model is implemented in a specially developed model environment and solved for a dynamic, illustrative use case. Subsequently, logistical target variables are evaluated in order to assess the solution of the optimization model. The exemplary application of the optimization model demonstrates the feasibility of modeling cellular transportation with automated guided vehicles and evaluating its performance based on logistical target variables.
AGV, cellular transport units, optimization model, simulation, logistical target values
This article examines the use of point clouds as a geometric data basis for factory planning and compares different mapping techniques for generating these point clouds. Data and information acquisition is a crucial step in factory planning and thus in developing efficient production processes. In this context, different mapping techniques are analysed: photogrammetry (using drones and action cameras) and LiDAR scans (performed both from drones and from the ground).
The methodology and results of this investigation are discussed in detail, highlighting the advantages and disadvantages of each mapping technique. The focus is on comparing the generated point clouds in terms of completeness, recognisability and geometric tolerance. This comparison provides valuable insights into which technique is best suited for the data acquisition of factory planning. The outlook of this paper includes the further development of recording techniques, particularly with regard to autonomously flying drones. In the future, these could enable more efficient and precise data acquisition for factory planning and thus further strengthen the basis for optimising production processes.
Drone, Photogrammetry, LiDAR, Point cloud, Factory planning, Data acquisition
Around half of the currently 30,000 active wind turbines in Germany will reach the end of their service life by 2030, which is generally defined by the manufacturer as 20 years of operation. The most common strategy for the subsequent use of a wind farm is repowering, provided this is (legally) possible at the respective location. One option for dealing with old turbines is to resell them. At the time of repowering, in Germany after an average of around 17 years, the wind turbines usually still have a remaining operating time of several years before critical parts such as generators fail.
This article presents a machine learning model for predicting the resale value of used wind turbines. This model can be used to approximately predict the resale value of comparable wind turbines based on certain input parameters such as the power output or the age of the wind turbines. The model was trained using an adjusted data set from an online trading platform for wind turbines. The necessary pre-processing steps such as the removal of extreme outlier values and the addition or replacement of missing or incorrect wind turbinespecific data from a second data source using a self-developed matching algorithm are presented. Finally, the prediction accuracy of different ML algorithms is tested using test data to find the best method for predicting the resale value of wind turbines.
Renewable energies, wind turbines, resale values, machine learning, data science
The article addresses a method for generating project schedules for factory relocations based on a planned layout concept in reorganisation projects. The layout is modelled in a cell grid with cells of uniform edge length. The factory objects are arranged in this grid for both the actual and the target layout state. Further input parameters relate to the required time and personnel resources according to several operations. A two-stage optimisation algorithm is presented, which first checks a given solution for layout feasibility and then generates and solves a project scheduling problem on this basis. Accordingly, elements of the facility layout problem are integrated into a resource constrained project scheduling problem. The process steps of generating and evaluating of the project schedule are further embedded in a genetic algorithm, which successively improves the solution. The project schedules for relocation are evaluated through a combination of the resulting project duration and the downtimes of all factory objects. The aim of the optimisation is to minimise both objective values considering a weighting factor. The article concludes by validating the method using a practical example.
factory planning, relocation planning, reorganisation, project scheduling, project planning
A continuously growing number of product variants increases the demands on the flexibility of intralogistics transportation. One way to achieve greater flexibility is the use of cellular automated guided vehicles, which can be variably interconnected depending on the size of the product to be transported. This article explains the characteristics of cellular automated guided vehicles and the relationships between influencing variables of the cellular transport system and economic and logistical target variables.
Intralogistics, automated guided vehicles, cellular transport units
Supply chain resilience is massively gaining importance for manufacturing companies in times of severe disruption due to crises. Supplier selection is a key aspect of building a resilient supply chain. Currently, however, there is no holistic method for supplier selection that takes resilience into account. This paper therefore presents a research project that aims to develop an assessment measure for resilience in the context of supplier selection. The aim is to consider the existing resilience from the supplier company’s perspective and the required resilience from the selecting company's perspective.
Logistics, Supplier Selection, Resilience, Supply Chain, Supply Chain Management
The realization of a planned layout concept represents a complex subtask within factory planning. In particular, the temporal arrangement of the necessary relocation steps, taking into account existing restrictions, is usually carried out manually according to the current state of the art. Therefore, an easy-to-use method for planning a factory move for reorganization projects was developed in a research project, which can be applied by companies in a practical context.
factory planning, removal planning, project scheduling, optimization, operations research
The realization of reorganization projects represents a complex and independent planning task within the framework of factory layout planning. Only little methodical knowledge exists, which considers the temporal, spatial and organizational restrictions in the creation of a schedule. This paper aims to present the interdependencies in the planning and execution of realization projects and thus to provide a basis for discussion for further investigations in the field of scheduling factory relocations for the reorganization of factory objects.
factory planning, relocation planning, project planning, effect modeling
A volatile, non-transparent market environment leads to fluctuations in the load on production capacities in the manufacturing sector, which are reflected within production in the over- or underutilization of machines and persons. Small and midsized enterprises (SMEs) are expecting increasing volatility, which is accompanied by an increase in the frequency of market and economic cycles. For SMEs it is difficult to cope with these fluctuations. Capacity sharing platforms can be a solution for this challenge. Platforms are available in different forms, but not used by companies often, because of prevailing scepticism in different fields. Therefore, a methodology will be developed to provide a decision support for or against platform usage. Additionally, the platform type choice will be supported, and the changes of logistic and economic indicators will be considered. With this information companies can make a qualitative decision, and the existing inhibitions can be alleviated.
capacity sharing, decision support, supplier and consumer view, logistic and economic indicators
The internal supply chain in companies includes all areas from procurement to shipping. It is characterised by a heterogeneous process landscape, often accompanied by repetitive, administrative tasks. These are usually associated with a high level of manual effort and a high potential for errors. An example of this is the manual entry of delivery notes into an enterprise resource planning (ERP) system. Even incremental improvements already help SMEs enormously to cope with the heterogeneity of processes in the internal supply chain. Robotic Process Automation (RPA) is a promising approach to this. RPA offers the potential to automate administrative processes in internal supply chain that previously did not seem automatable.
Logistik, innerbetriebliche Lieferkette, robotic process automation, RPA
The reorganization of factory objects in the restructuring of existing factories is associated with numerous challenges. This article provides an overview of possible conflicting goals and key factors influencing the success of the project.
Factories are subject to continuous change. Ever shorter development cycles in the manufacture of different products lead to an increased need for restructuring of affected manufacturing structures. In the context of factory planning projects, the focus is on the design of the layout under the influence of individual framework conditions. The relocation steps necessary for realization are usually determined only after the layout design has been completed. However, the planning and preparation of the relocation represents an independent project task with regard to the objectives and complexity. Within the scope of the research project on the "Development of a Method for the Optimal Planning of the Relocation of Factory Objects in the Course of the Realization of a New Factory Layout" (OptiFaU), fundamental interrelationships in the planning and execution of factory relocations are investigated and discussed with regard to their significance for the success of the project. The aim of the project is to provide planning persons (e.g. relocation service providers or factory planners) with a possibility to evaluate relocation alternatives.
relocation planning, project planning, scheduling, factory planning, reorganization
How can companies get the most out of their manufacturing and be economically successful even in a high-wage location? A Manufacturing Execution System – a process-oriented level of a multi-layer production management system – can help. This enables companies to optimize their production planning and control.
A large number of small and medium-sized enterprises (SMEs) currently still do without this support because the effort required to introduce such a system appears too great. One way to reduce the effort involved is to prepare comprehensively for the MES introduction. An "MES Readiness Check" should provide support for this preparation. It reveals the demands that this introduction phase places on companies. The company can check whether it meets the necessary requirements.
Manufacturing Execution System, MES, Digitalization
Storage planning is an important element of the factory planning and a significant competitive factor in times of an increasing global market. The selection of a suitable storage, commissioning and transport system (sct system) is a major challenge for companies, because of the increasing number of new sct systems with different features. The level of automation and versatility of these systems are intransparent and the required level of both for a certain company is unknown. To identify the level of versatility of sct systems a method based on versatility characteristics assigned to the versatility enablers was developed. To determine the required versatility of sct systems for a particular company, a catalogue of change drivers was created. For the level of automation of sct systems, the requirements resulting from product characteristics and performance requirements of the warehouse were identified. The performance of the sct systems depends on the automation level, which can be set by influencing factors such as the degree of digitalization. The required level of automation must be determined by restrictions of the company and the identified possibilities of the systems. At the same time, it is required to consider the costs of the systems as well as their possible combinations. Therefore, to save costs, the aim is also to consider systems which do not fit perfectly to the required versatility and automation level for a company but are still at an acceptable level.
storage, commissioning and transport systems, automation and versatility
During the assembly of large-scale products, disruptions often occur. To reduce these disruptions, a straightforward approach to their systematic processing is needed. This should automatically identify similar disruptions and independently suggest sensible corrective measures. For this, the disruptions are first collected and characterized and a model for practical information flows is created. Then, in a multi-stage similarity search, similar disruptions are identified, and suitable corrective measures are derived.
Disruption management, single and small batch assembly, large scale products, similarity search
Since free?aces for new buildings are limited or not available at all, redensification is a promising approach to generate new living space. This can be both the extension of existing buildings by further storeys and the vertical extension or change of use of other building structures. Modular house construction takes this objective into account because a large part of the added value is generated before construction begins. Its advantages are now set against the logistical challenges of post-densification.
Modular house construction, post-densification, construction sites, production planning and control
On inner-city construction sites, there is usually only a limited amount of space available. This increases the complexity in the implementation of corresponding construction projects and at the same time the risk of postponements. Both the composition of the demand for specific types of space and the development of demand during the construction period should be taken into account in the course of scheduling. One way of assessing the demand for space is to introduce the potential for conversion as an indicator of the property of a specific space to be able to adapt flexibly in the event of possible short-term changes in the construction project. This can be used to create an evaluation basis that initially provides decision support for project planners and can subsequently be integrated into optimising procedures for scheduling. This will have a positive influence on the quality of a schedule in connection with its robustness.
Scheduling, construction management, project planning, production planning, construction sites
In the production of stock goods, manufacturing companies are faced with uncertain customer demand. In order to counter uncertainties, an increased inventory is necessary in order to be able to meet customer demand. The costs incurred are influenced by the ordering behaviour given the forecast uncertainty. Ordering behaviour is largely determined by the ordering policy. Therefore, the influence of forecast uncertainty and ordering policy on the resulting storage costs was investigated by means of sensitivity analyses. Accordingly, forecast uncertainties require larger inventories under the (t, S) policy than under the (s, q) policy.
stock planning, ordering policy, forecasting
Software for an Automated Multidimensional Factory Layout Optimisation: Layout planning is a complex planning task in the context of factory planning, which up to now has usually needed to be carried out manually. Although many optimisation methods for the underlying problem have been developed in the past, they were only applicable to a small group of experts, mostly from universities. Therefore, an easy-touse software for layout planning was developed in a research project to provide companies with access to these optimisation methods.
Factory planning, facility layout planning, optimization, operations research, software
Demographic change and the associated population growth in large cities make it increasingly difficult to create affordable housing. There is also a lack of available building land for potential new buildings. One approach to alleviate the housing shortage in large cities is modular building post-compaction. In this context, prevailing framework conditions are characterized by limited available space, a complex infrastructure or the consideration of the burden on residents. The lack of description models for associated construction sites, as well as for the organisation and control of necessary processes, still stand in the way of their widespread use. This refers in particular to the interactions of the parameters mentioned and their effect on the logistic performance of such a construction site. This article therefore describes a method for the organization and control of construction site processes in the modular building post-compaction with the aim to be able to plan and carry out such con-struction projects efficiently and with little effort. The users shall be provided with a process description of the planning of construction site equipment and process flow, as well as with a decision support in case of disturbances of the process in the operative operation.
urbanization, demographic change, construction sites, production planning and control
In current approaches to factory planning, the influences of transport systems are not taken into account in the layout planning process. Means of transport selection and transportation network planning takes place downstream of layout planning. The effects of transport system selection on the design of the factory layout are therefore only considered at the end of the factory planning process. The selection of certain transportation systems can therefore require extensive adjustments to the layout. This article describes a concept for an expert system that integrates transportation network planning into the layout planning process in addition to transportation system selection. The expert system should interpret the expert knowledge for the selection of transport systems on the basis of fuzzy logic and generate the later factory layout, as well as the transport networks, automatically on the basis of defined input data.
factory planning, layout planning, transport systems, fuzzy logic
