This document discusses computer system validation and process validation. It defines process validation as establishing evidence through all stages of production to consistently deliver quality products according to regulations. The FDA defines process validation as providing high assurance a process consistently meets specifications. Key concepts include three validation stages: process design, process qualification, and continued verification. There are four types of validation: prospective, retrospective, concurrent, and revalidation when changes are made.

1. Computer System Validation
By: Payam Khorramshahi

2. Process Validation
Collection and evaluation of data from the process design stage
throughout production
Purpose  Establishment of scientific evidence to provide a
process capable of consistently delivering quality products.
Requires  current Good Manufacturing Practices (cGMP) for
validating pharmaceutical and medical device production.
• Refer to: 21 CFR 211 for finished pharmaceuticals
• Refer to: 21 CFR 820 for medical devices

3. FDA Regulation
The U.S. Food and Drug Administration (FDA) has
proposed guidelines with the following definition for
process validation:
“Process Validation is establishing documented
evidence which provides a high degree of assurance
that a specific process consistently produces a product
meeting its predetermined specifications and quality
attributes”

4. Key Concepts
The process validation activities is described in
three stages:
Stage 1 – Process Design
Stage 2 – Process Qualification
Continued Process Verification

5. Definitions
 Process Design  The commercial process is defined
during this stage based on knowledge gained through
development and scale-up activities.
 Process Qualification  During this stage, the process
design is confirmed s being capable of reproducible
commercial manufacturing.
 Continued Process Verification  Ongoing assurance
is gained during routine production that the process
in a state of control.

6. Types of Process Validation
A.Prospective Validation
B.Retrospective Validation
C.Concurrent Validation
D.Revalidation

7. Definitions
 Prospective Validation  Establishing documented evidence prior to
process implementation that a system does what it proposed to do
based on preplanned protocols.
 Retrospective Validation  Is used for facilities, processes, and
process controls in operation use that have not undergone a formally
documented validation process.
 Concurrent Validation  Is used for establishing documented
evidence that a facility and processes do what they purport to do,
based on information generated during actual imputation of the
process.
 Revalidation  Revalidation means repeating the original validation
effort or any part of it, and includes the investigative review of
existing performance data.

8. Correlations Between Stages and Types
of Validations

9.  Revalidation is required since 
When any changes are made in to the process or its environment is very
essential to ensure that it should not have any adverse effects on :
• Product Quality
• Process Characteristics