Glossary · HMI, SCADA and operations
Electronic signature
Also known as: E-signature
German: Elektronische Signatur
In regulated production systems, an electronic signature is a computer data compilation of symbols executed, adopted or authorized by an individual as the legally binding equivalent of a handwritten signature, linked to the signed record and showing the signer, time and meaning of the signature.
- HMI and SCADA
- Process industry
In one sentence
An electronic signature is the binding electronic equivalent of a handwritten signature, linked to a record with signer, time and meaning.
Example
Before a changed recipe is released, the HMI asks the production supervisor for user ID and password and records the signature with the meaning "approved".
How it applies
- Engineering: Signatures must be unique to one person, linked to their record so they cannot be copied, and show printed name, date and time and meaning (such as review, approval, responsibility). Non-biometric signatures use at least two components, such as user ID and password. Many HMI, SCADA and batch systems offer signature functions for regulated use.
- Compliance: In US pharmaceutical and medical device manufacturing, 21 CFR Part 11 (electronic records and signatures) applies; in the EU, EU GMP Annex 11 (computerized systems). The software feature alone doesn't make a system compliant; procedures, validation and user management are required.
- Documentation: SOPs define which actions require a signature and what each meaning implies. User documentation must describe the signing dialog and what happens when a signature is rejected.
Electronic signature vs. digital signature
An electronic signature in the regulatory sense is defined by its legal effect. A digital signature is a cryptographic technique; it can implement electronic signatures but is not required by 21 CFR Part 11 for every case.