How do you ensure an even balance between thoroughness and efficiency when you're evaluating potential vendors?

Start with clear, concise criteria that align with your business needs and objectives. This includes quality, cost, reliability, and service levels. Having predefined criteria speeds up the evaluation process and ensures consistency.

Implement a tiered or phased approach to vendor evaluation. Start with an initial screening based on essential criteria to narrow down the pool. Then, conduct a more detailed assessment for the shortlisted vendors. This approach ensures thoroughness where it's needed while maintaining overall efficiency.

Every supplier has a different approach while dealing with customers & OEMs during the evaluation phase. To get the best result ensure that all assessments are informed beforehand including SAQ (self-assessment questionnaire) are requested and later verified with on-site/virtual evaluation. This activity not only verifies the supplier's claims on their capabilities but also provides a holistic view of the supplier's authenticity and genuineness. 

Sabine said it well.  Anyone with a one-size-fits-all approach is either working too hard or missing opportunities.  We try to consider the business value, and then we do a risk analysis during the supplier selection process (once we're down to finalists as it can be a lift) if it's a substantive review, and the output of the risk analysis drives a significant amount of variation in how we consider and potentially ultimately onboard the supplier.  Nothing earth shattering in that risk assessment (cyber security, financial, reputational, business criticality, etc.)

By starting with an understanding of the business problem the supplier is supposed to solve for us. Based on that, there is a certain risk in the relationship and an expected duration. Based on these factors, we determine what to evaluate, how thoroughly, and assign a priority.