With the growing recognition of the citizen's role in service demand as a customer and quality of service delivered by governmental employee, there is an increased motivation on building citizen trust in governmental institutions in delivering services. By using human sigma through enhancing employee and customer encountered and engagement, the research aims to contribute how the interaction and engagement will support citizen trust in quality of public service.  Building citizen trust will increase by imbedding credible governance processes and practice in governmental institutions and scheme to guarantee o over all service quality system and achieve quality of life in the community at large. New Public Management (NPM) accepts the assumption that the behavior of people, individually and collectively, is driven by self-interest and emotions. This means that governmental institutions, departments and employees will act to ensure their own continued viability and survival through its principles. The proposed model has been tested through an analysis of multiple regression analysis results provide evidence measured the variables of service quality through employees and customers' engagement that support citizen trust in government services. The effective adoption of human sigma leads to achieving significant improvement in the level of customer and employee engagement. Customer and employee trust plays an influential role in reflecting the best practice of good governance. Trust based good governance is significantly contingent on using human sigma triggered customers and employees engagement accordingly as a conclusive wrap up the bank management should seek to accelerate the effective adoption of human sigma with a view toward increasing the level of trust-based good governance that can be attributed to achieve superior levels of customers and employees engagement at the bank level.