Categorizing modularization strategies to achieve various objectives of building investments

Figures & data

Figure 1. Slot, bus and sectional architectures of component interfaces.

Figure 2. Theoretical framework for classifying modularization strategies according to the main objectives of building investments.

Table 1. Description of cases and multiple sources of evidence (triangulation).

Case	Modularized system	Main objective	Multiple sources of evidence
(A) Prefabricated façade producer in Brazil	Prefabricated façade system	Quality	Two interviews with the producer–owner and the technical manager
			Visit to the production factory in Brazil
			Direct observation of the construction process onsite
			Product feature documents
(B) Prefabricated concrete wall system in Brazil	Prefabricated concrete wall system	Cost-efficiency	Three interviews with the technology, planning and production managers
			Visits to three production factories and five worksites in Brazil, which have a common owner
			Direct observation of the construction process onsite
			Analysis of design documents, budgets and schedules
(C) Prefabricated concrete element system in Finland	Concrete element system for residential buildings	Cost-efficiency	One interview with the development manager of the largest element provider
			Historical document on concrete element construction in Finland, produced by the Concrete Industry Association
			Guideline documents regarding the elements and their structures (element types, modular sizing, interface details)
(D) Bathroom producer in Brazil	Preassembled bathrooms	Quality	Two interviews with the operational manager and one production engineer
			Visits to two production factories and three worksites in Brazil
			Analysis of design documents, budgets and schedules
(E) Hotel project in California	Preassembled bathrooms	Quality	Interview with the project’s general contractor
			Worksite visit
			Inspection of the model bathroom module
(F) Hospital project in Florida	Preassembled patient room wall components	Innovativeness	Two documents describing the project, written by the hospital designers
			Seven media articles on the project
			Two workshops with industry experts and consultants
(G) Hospital operating room producer in Finland	Turnkey operating room from prefabricated components	Quality	Four interviews with the representatives of component producers and one with a customer
			Visit to the production factory
			Product feature documents and assembly schedules
			Video of production process
			Two workshops with industry experts and consultants
(H) Hospital project in Missouri	Modular hospital building	Schedule	Interview with the module producer
			Visit to the module production factory
			Project background and progress documents produced by the building designers
			Floor plans
			Workshop with industry experts and consultants
(I) Modular building system producer in Finland	Transferable modular health care facility	Flexibility in use	Four interviews with the producer’s representatives and five user interviews
			Visit to the module production factory and the healthcare facility site
			Product feature documents
			Video of production process
			Two workshops with industry experts and consultants

Table 2. Summary of the modularization strategies of the cases.

Case	Objectives	Organization	Product architecture	Production system	Platform assets	Support for propositions
A	(1) Quality (2) Schedule (3) Maintenance	Collaborative	Partially modular Bus/sectional interfaces	Non-volumetric preassembly	People, knowledge, processes	Yes (P2)
B	(1) Cost-efficiency (2) Schedule	Integrated	Almost completely modular Sectional interfaces	Non-volumetric preassembly	People, knowledge, processes, components	Yes (P2)
C	(1) Cost-efficiency (2) Supply chain flexibility (3) Schedule	Supplier(s)-driven	Almost completely modular Sectional interfaces	Non-volumetric preassembly	Knowledge, processes, components	Partly (P2); Industry-driven system
D	(1) Quality (2) Onsite labour costs	Collaborative	Partially modular Bus interfaces	Volumetric preassembly	People, knowledge, processes	Yes (P2)
E	(1) Quality (2) Schedule (3) Innovativeness	Project organization-driven (design)/collaborative (delivery)	Partially modular Bus interfaces	Volumetric preassembly	People, knowledge, processes	Yes (P1 and P2)
F	(1) Innovativeness (2) Quality (3) Schedule (4) Labour costs	Project organization-driven	Partially modular Bus interfaces	Volumetric and non-volumetric preassembly	People, knowledge	Yes (P1)
G	(1) Quality (2) Schedule (3) Maintenance	Supplier-driven	Partially modular Slot/sectional interfaces	Non-volumetric preassembly	People, knowledge, processes, components	Partly (P2 and P3); more supplier driven than objectives and product architecture assume
H	(1) Schedule (2) Access to skilled labour	Collaborative	Completely modular Sectional interfaces	Modular buildings	People, knowledge, processes	Yes (P2)
I	(1) Flexibility in use (2) Schedule (3) Quality	Supplier-driven	Completely modular Sectional interfaces	Modular buildings	Processes, components	Yes (P3)

Table 3. Identified challenges in modularization.

Case	Modularization strategy	Identified challenges
(A) Prefabricated façade producer	Collaborative	Interfaces among subsystems (structure, masonry, windows, etc.)
		Specialized labour
		Few market options available
		Performance must be evaluated in multiple-storey buildings
(B) Prefabricated concrete wall system	Integrated	Guarantee of economy of scale (typical building project life cycle of 48 months, excluding maintenance)
		Specialized labour
		Customer rejection
(C) Prefabricated concrete element system	Supplier(s)-driven	Definition of standard details and connections
		Lack of competition among modularized systems
		Lack of innovativeness as product architecture is locked
(D) Bathroom producer	Collaborative	Guarantee of economy of scale
		Transportation costs
		Management of interfaces with subsystems
(E) Hotel project	Project organization-driven (design)/collaborative (delivery)	Management of assembly work and interface tolerances
		Learning diminishes performance in first few installations
		Module provider did not participate early enough in design
		Seismic connections were overlooked
(F) Hospital project	Project organization-driven	Interfaces among subsystems
		Necessity of first-run prototypes
(G) Hospital operating room producer	Supplier-driven	Needs both trade and location-based division of procurement
		Management of customer expectations in design
(H) Hospital project	Collaborative	Management of heavy equipment
		Relationship between general contractor and module supplier
(I) Modular building system producer	Supplier-driven	High company investment in the beginning
		Customer rejection due to poor image of modular solutions

Figure 3. A framework for classifying modularization strategies according to the main objectives of building investments.