warranty of quality meaning in Chinese

质量保证
质量担保

Article 62 the system of the warranty of quality shall be established for construction projects
第六十二条建筑工程实行质量保修制度。
I do believe they may have strongly special technology skills to complete but the problem is , how could they ensure they could complete it before the deadline of time with warranty of quality
我相信他们有非常强的，特殊的技能来完成项目，但是他们如何能够保证“按时”完成并且质量也能够有所保证呢？