Road transports face increasing societal challenges with respect to emissions, safety, and traffic congestion, as well as business challenges. Truck automation, e.g. self-driving trucks may be utilized to address some of these issues. Autonomous transport vehicles may be characterized as Cyber-Physical Systems (CPS). A drawback is that CPS significantly increase technical complexity and thus introduce new challenges to system architecting.

A product architecture is the interrelation between physical components and their function, i.e. their purpose. Product architectures can be categorized as being modular or integral. The main purpose of a modular architecture is to enable external variety and at the same time internal commonality. Products with a modular architecture are configured from predesigned building blocks, i.e. modules. A stable module, which is a carrier of main function(s) has standardized interfaces, is configured for company-specific reasons, which means it supports a company-specific (business) strategy.

In this thesis, the present state at the heavy vehicle manufacturer Scania, concerning product architecting, modularization, product description and configuration is investigated. Moreover, a new clustering based method for product modularization that integrates product complexity and company business strategies is proposed. The method is logically verified with multiple industrial cases, where the architecture of a heavy truck driveline is used as a test bench. The driveline contains synergistic configurations of mechanical, electrical and software technologies that are constituents of an automated  and/or semi-autonomous system, i.e. the driveline may be characterized as a CPS. The architecture is analyzed both from technical complexity and business strategy point of view. 

The presented research indicates that a structured methodology which supports the development of the product architecture is needed at Scania, to enable control of the increasing technical complexity in the Cyber-Physical Systems. Finally, configuration rules are identified to be highly important in order to successfully realize a modular product architecture. A drawback with this approach is that the solution space becomes hard to identify, therefore a complete and flexible product description methodology is essential. The results from the case studies indicate that clustering of a Product Architecture DSM may result in a modular architecture with significantly reduced complexity, but with clusters that contain conflicting module drivers. It is also identified that the new modularization methodology is capable of identifying and proposing reasonable module candidates that address product complexity as well as company-specific strategies. Furthermore, several case studies show that the proposed method can be used for analyzing and finding the explicit and/or implicit, technical as well as strategic, reasons behind the architecture of an existing product. 

Road transports face increasing challenges with respect to safety, legislations on lower emissions and traffic congestion, as well as numerous business challenges related to paradigm shifts in technology, tightened delivery times and cost constraints. Combination of truck electrification and automation may be utilized to address some of these issues. Electrified and autonomous transport vehicles may be characterized as Cyber-Physical Systems (CPS). A drawback with CPS is the extensive increase of technical complexity, which introduce new challenges to Systems Engineering (SE). The added complexity is preferably targeted in the product architecting development stage of SE. 

Product architecting involves conceptual system design, module identification (clustering) and product layout design. A product architecture is the interrelation between physical components and their function, i.e. their purpose. Product architectures can be categorized as being modular, hybrid or integral. A modular architecture is a strategic means to deliver external variety and internal commonality. Modular subsystems enable concurrent development and modularization is, thus, a structured method to manage technical complexity. In this thesis, a new clustering-based methodology and process for heavy-duty truck modularization that integrates technical complexity, company business strategies and physical interference is proposed.  The main hypothesis behind the  presented research is that computer-based product architecture clustering analysis benefit from a quantitative complexity measure, as well as means to represent (model) and communicate product architecture related complexity. A variety of industrial cases of heavy-duty truck subsystems are used to describe the proposed methodology and to verify its performance, i.e. how well the proposed methodology and process supports the SE process. All investigated subsystems  contains synergistic configurations of mechanical, electrical and software technologies, i.e. they may be characterized as CPS. 

The presented research concludes that the proposed modularization methodology and process is capable of supporting the SE process by improving the quality of the module identification stage, by adding business strategies and physical interference to product architecture clustering. Moreover, it is confirmed that the new methodology is both scalable and flexible, allowing the consequences of different architectural trade-offs to be analyzed independently or combined depending on purpose. Furthermore, the newly developed architectural representations showed to make architectural discussions in general and modularity discussion in particular with and between domain experts efficient. Finally, the case studies clearly shows that the clustering results depend on the relative weights of the different types of component relations that are represented in the product architecture DSM (Design Structure Matrix). However, the importance of these weights are reduced when multiple business strategic and physical interference constraints are introduced.

Vägtransporter står inför ökade samhällsutmaningar med avseende på säkerhet, lagkrav gällande lägre utsläpp, trafikstockningar, samt affärsutmaningar relaterat till ett paradigmskifte i teknik, kortare leveranstider och kostnadsbesparingar. Lastbilselektrifiering och automation kan användas för att lösa några av dessa problem. Elektrifierade och autonoma transportfordon kan kännetecknas som cyberfysiska system, förkortat CPS. En nackdel med CPS är den avsevärt ökade tekniska komplexiteten, vilket introducerar nya utmaningar till Systems Engineering, förkortat SE. Den ökade tekniska komplexiteten kan företrädesvis hanteras under utvecklingen av produktens arkitektur inom SE.

Utvecklingen av en produktarkitektur består av följande steg; konceptuell systemkonstruktion, identifiering av moduler (klustringsanalys) och utformning av produktlayouten. En produktarkitektur är sambandet mellan fysiska komponenter och deras funktion, d.v.s. deras syfte. Produktarkitekturer kan kategoriseras som modulära, hybrider eller integrerade. Huvudsyftet med en modulär arkitektur är att möjliggöra en yttre variation och samtidigt inre enhetlighet. Modulära delsystem möjliggör parallell utveckling och modularisering kan därför ses som en strukturerad metod för att hantera teknisk komplexitet. I den här avhandlingen föreslås en ny klustringsbaserad metod och process för modularisering av tunga lastbilar som integrerar teknisk komplexitet, företagsspecifika affärsstrategier och fysisk interferens. Den huvudsakliga hypotesen bakom den presenterade forskningen är att datorbaserad klustringsanalys av produktarkitektur förbättras av ett kvantitativt komplexitetsmått, samt nya sätt att representera (modellera) och kommunicera produktarkitekturrelaterad komplexitet. Ett antal olika industriella fallstudier som behandlar delsystem av tunga lastbilar används för att beskriva den föreslagna metoden och för att verifiera dess prestanda, d.v.s. hur väl den föreslagna metoden och processen stödjer SE-processen. Samtliga undersökta delsystem innehåller samverkande konfigurationer av mekaniska, elektriska och mjukvaruteknologier, d.v.s. de kan kännetecknas som CPS.

Slutsatsen av den presenterade forskningen är att den föreslagna modulariseringsmetoden och processen stödjer SE-processen genom att förbättra kvaliteten under identifieringen av moduler. Detta möjliggörs genom att addera affärsstrategier och fysisk interferens under klustringsanalysen av produktarkitekturen. Utöver det bekräftas även att den nya metoden både är skalbar och flexibel, vilket gör att konsekvenserna av olika arkitekturella avvägningar kan analyseras oberoende eller samtidigt beroende på syfte. Därtill bekräftas att de nyligen utvecklade arkitekturrepresentationerna effektiviserar arkitekturrelaterade diskussioner, och i synnerhet diskussioner gällande modularisering mellan domänexperter. Slutligen visar fallstudierna att klustringsresultaten beror på de relativa vikterna för de olika typerna av komponentrelationer som representeras i en produktarkitektur DSM (Design Structure Matrix). Betydelsen av dessa vikter minskar dock när affärsstrategiska och fysisk interferens begränsningar införs.