https://www.mdu.se/

The purpose of a quarry is to extract rock material to deliver gravels, cement and asphalt to its customers. These products are important input to the construction and maintenance of road infrastructure, buildings and more. The operation of quarry and road work sites is similar to factory production, since it contains sequential production processes, tasks and activities to produce the output product. Compared to the factory, the quarry and road work processes are generally not synchronized and controlled towards the overall throughput in real-time. Some sites control parts of the production but do generally not utilize real-time technologies for the whole site and all its activities. This fact indicates a general improvement potential in increased productivity, but also unsolved challenges for the same reason.

This thesis investigate how Lean thinking utilizing real-time control and wireless communication can be used to improve productivity and safety in the operation of quarry and road construction. The main overall contribution is the identified operational improvements, its use cases, the system design constraints and challenges as well as assessed impact in productivity, energy efficiency and safety if introducing wireless real-time control to the site operation.

The results include the presentation and demonstration of a developed method based on Lean value stream mapping, for identifying wastes in sequential processes and activities including mobile machines. Further it investigates the performance and evaluates how the latest developments of wireless communication and vehicular ad-hoc networks (VANET) can be utilized within the quarry and road construction operation. The main system requirements and constraints are identified and the tradeoffs and gains in terms of system design, communication coverage, energy consumption and safety for the identified use cases are presented.

Bergtäckter uppfyller viktiga funktioner eftersom de producerar olika typer av stenkross, cement och asfaltsprodukter nödvändiga för alla typer av byggnationer såsom vägar, tunnlar, broar och byggnader och dess underhåll.  Bergtäckt och vägarbetsprocessen består likt en industriell produktionsanläggning av sekventiella aktiviteter för att producera slutprodukten.  Men i motsats till moderna produktionsanläggningar så är inte alla aktiviteter och maskiner styrda mot genomflödet för anläggningen, vilket gör att aktiviteter med överkapacitet genererar kostnader i form av lager och onödig resursåtgång. Detta faktum indikerar en potential i produktivitetsförbättring för dessa segment, men också olösta utmaningar.

Den här uppsatsen utreder hur den inom produktionsteknik välkända Lean filosofin tillsammans med den senaste utvecklingen av trådlösa styrsystem kan användas för att förbättra produktivitet och säkerhet för bergtäckts och vägarbetssegmentet. Det huvudsakliga bidraget är identifierade förbättringar av produktivitet och säkerhet i den operativa verksamheten, dess användarfall, systemdesignens komponenter, utmaningar och begränsningar vid introduktion av trådlösa styrsystem.

Resultatet inkluderar redogörelsen av en utvecklad och demonstrerad metodik baserad på Lean - värdeflödesanalys för att identifiera slöseri i operativ verksamhet inkluderande mobila maskiner och fordon. Dessutom undersöker och utvärderar uppsatsen prestandan och användbarhet av den senaste utvecklingen av trådlösa kommunikationssystem baserat på ad-hoc nätverk för vägfordon. De övergripande systemkraven identifieras och nödvändiga avvägningar diskuteras i form av systemdesign, kommunikationsprestanda, kostnad, energibesparingar och säkerhetsförbättringar för segmenten.

The purpose of a quarry is to extract rock material to deliver gravel and raw material to its customers. The products can be further processed to e.g., extract minerals such as iron or to produce cement and asphalt. These products are an important input to the construction and maintenance of road infrastructure, buildings, and more. The operation of quarry and road work sites is similar to the manufacturing industry since it contains sequential processes to produce the output product. Within the operation, there are cyclic transport activities that in general are not synchronized and controlled in real-time towards the overall throughput. This fact indicates a potential to increase productivity but also points at unsolved challenges.

This thesis investigates how Lean and systems thinking combined with real-time control and optimization technologies can be used to improve productivity and safety in the transport operation within quarry and road construction. The main contributions are the identified operational improvements, its use cases, the system design constraints, operational characteristics, and models as well as assessed impact in productivity, energy efficiency, and safety.

The results include the development and demonstration of a method based on Lean value stream mapping, for identifying wastes in sequential processes and activities including mobile earthmoving machines. Operational wastes of 33% are presented from real world operations. Related fuel savings of 42% are measured in controlled environments. Further, the thesis presents and assesses a system design for transport optimization purpose. A study of how wireless communication and vehicular ad-hoc networks (VANET) can be utilized and its performance within the quarry and road construction operation is presented. The main system requirements and constraints are identified, and the trade-offs are discussed in terms of system design with a system of systems perspective. Energy consumption models are developed for optimization purposes and the key characteristics of real world operation is identified. Finally, a prototype system has been developed and tested in controlled and operative environments. In controlled trials, a fuel reduction of 20% for individual machines was obtained using the suggested optimization technique.