This paper presents an investigation on operational excellence (OpX) models of sustainable supply chains (SSCs) in Sri Lankan manufacturing organizations during Covid-19 pandemic. This investigation consists of multiple case studies of Sri Lankan manufacturing organizations in following industries: rubber and plastic products, wearing apparels, paper and paper products. Based on a pre-existing OpX model, six Critical Success Factors (CSFs) were identified in terms of SSCs. This research was conducted as an exploratory case study where data is collected through in-depth interviews, company websites/reports. By using a deductive approach, findings of CSFs effecting behaviour of OpX models are displayed. Thematic and Content analysis on the behavior of OpX models in SSCs are non-generalizable beyond this research. The findings display the organization in respect to wearing apparels has a more sustainable approach to better manage their OpX model and more strategic Upper Echelons to gain better strategic outcomes before/during Covid-19 pandemic. The profile of a manager was vital in interpreting OpX models in their organizations. The study outcomes can inform organizations to prime their OpX model for a crisis of Covid-19 magnitude. The effects may be generalized further to other industries. The study describes connectivity of Upper Echelons Theory to OpX models and contributes to literature through a demonstration of CSF behaviours in OpX models of SSCs during the Covid-19 crisis.