The UK National Food Crime Unit's self-assessment questionaire has recently been revised. This 20-minute prompt to check for best practice in fraud resilience is particularly aimed at Small and Medium Enterprises (SMEs)
A curated link to the NFCU self-assessment is within the "Tools" list on the "Food Fraud Prevention" FAN pages. It is always worth a quick check for other tools on the list which might be a good fit for your own organisation.