## 9 Conclusions  
The latest advancements, mechanical performances, constraints, and future prospects of PFISBs are all examined in this study. This work then offers solutions for overcoming several obstacles to the widespread adoption of high-rise PFISB structures. The following findings are taken from this systematic review, critical analysis, and perspective, as well as the authors' more than ten years of expertise in this study direction:  
1. Prefabricated industrial steel construction is widely used in emergency and repetitive construction projects. Aluminum IMUs are brittle, and their high cost continues to be a considerable hurdle. Timber IMUs are frequently employed for low-rise applications, but steel and precas IMUs have been the industry standard for decades for high-rise PFISBs. It has been implemented in China, the UK, Japan, Singapore, Sweden, Australia, Germany, the Netherlands, the US, etc., as the most appropriate response to modern urbanization and high-level prefabrication. Future perspectives revealed that China plans to increase PFIC to 30% by 2026, 15% by 2025 in Australia, and over 5% in North America by 2023, proving that PFIC is a viable solution to future urbanization issues. 2. Multi-story PFISBs can be erected utilizing 3D IMUs fully serviced and prefinished in the factory and combined by IMC or HBS systems with a semi-modular 2D panelized IMU attached by a wet joint. Due to their distinctive form and construction, both panelized and volumetric PFISBs could cut the building time by more than 30 to 50%. The present design guidelines do not account for the uniqueness of the design, which impacts the quality and safety of the project. This requires the development of standards for PFISB technologies, especially in the areas of an explosion, vibration, fatigue, earthquake, winds, collapsing, and fire. 3. Prefabricated industrial steel buildings are classed as continuous and corner-supported IMUs made of lightweight or heavyweight steel. Cold-formed sections or weaker IMCs and detachable columns continuous and corner-supported IMUs support low-rise PFISBs. Heavyweight PFISBs provide a superior lateral and longitudinal stability when supported by hot-rolled SHS columns that distribute loads over multiple columns, making them more suitable for high-rise PFISBs. Primarily welded IMCs were used to tighten all PFISB types that exhibited a satisfactory performance; however, they are costly, of a poor quality, and require functional space for internal connection welding. Consequently, they are no longer utilized and manual or automated bolted, pre-tensioned, and post-tensioned IMCs are preferred. 4. For manually operating PFISBs, the IMC is often welded, bolted, and pre-stressed. Due to the substantial onsite labor required for the welded IMC, there is insufficient space for a secure weld quality and complete welding. The production efficiency of the bolted IMC is demanding. The building standards for a prestressed IMC are more strict and complex. The stiffness of the welded and prestressed IMC is superior and more susceptible to brittle failure than bolted joints to the prying failure. They prefer to drill holes to assemble, which may compromise the IMUs' sectional integrity and interior design or render it incapable of lifting forces. Recent advancements in the spring technology have enabled the development of various mechanical IMCs that do not require any operational area. However, these self-locking IMC cannot be removed once locked, making it difficult to reuse the IMUs' in case of accidental damage during service; thus, numerous IMCs with replaceable or detachable technologies for repeated use have recently been developed. These IMCs all have a reliable seismic, uplift, and shear resistance. Due to the discontinuity between the floor and wall diaphragms, there are substantial issues with the PFISBs' in- and out-of-plane stiffness and non-uniform lateral force transmission. No suitable study on the developed connecting system on the beams has been published. 5.