In this case study, we examine a real$-$world mega house construction project located on Robert Mugabe Street in Harare, Zimbabwe, called Atlas House This case showcases the successful implementation of Quality Assurance $($QA$)$ practices in a complex construction project. The project involves the construction of a large commercial complex by Cementers Zimbabwe $($Pvt$)$ Limited, in partnership with the real estate developer, Arosume Property Development $($PVT$)$ Ltd$.$ The architectural and design aspects are managed by Archicraft Architects, while various sub$-$contractors, including Vaka Concrete, Gonoh Electrical Services, and Seagate Plumbers Ltd$,$ are engaged in different phases of the construction.

Required: Explain the crucial role of supplier and subcontractor quality management in large$-$scale construction projects, referencing the engagement with Vaka Concrete, Gonoh Electrical Services, and Seagate Plumbers Ltd$.$ How did these partnerships ensure that construction materials and components met stringent quality criteria?