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Validacion de sistemas computarizados
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Appendix 5
Validation of computerized systems
1. General
2. System specification
3. Functional specification
4. Security
5. Back-ups
6. Validation
7. Validation of hardware and software
7.1 Hardware
7.2 Software
1. General
1.1 Computer systems should be validated at the level appropriate for
their use and application. This is of importance in production as well as in
quality control.
1.2 The use of a computer system includes different stages. These are
planning, specification, programming, testing, commissioning, document
operation, monitoring and modifying.
1.3 The purpose of validation of a computer system is to ensure an acceptable
degree of evidence (documented, raw data), confi dence (dependability
and thorough, rigorous achievement of predetermined specifi cations),
intended use, accuracy, consistency and reliability.
1.4 Both the system specifications and functional specifi cations should
be validated.
1.5 Periodic (or continuous) evaluation should be performed after the
initial validation.
1.6 There should be written procedures for performance monitoring,
change control, programme and data security, calibration and maintenance,
personnel training, emergency recovery and periodic re-evaluation.
1.7 Aspects of computerized operations that should be considered
during validation include:
— networks
— manual back-ups
— input/output checks
— process documentation
— monitoring
— alarms
— shutdown recovery.

2. System specifi cation
2.1 There should be a control document or system specifi cation. The
control document should state the objectives of a proposed computer system,
the data to be entered and stored, the flow of data, how it interacts with
other systems and procedures, the information to be produced, the limits of
any variable and the operating programme and test programme. (Examples
of each document produced by the programme should be included.)
2.2 System elements that need to be considered in computer validation
include hardware (equipment), software (procedures) and people (users).
3. Functional specifi cation
3.1 A functional or performance specification should provide instructions
for testing, operating, and maintaining the system, as well as names of the
person(s) responsible for its development and operation.
3.2 The following general aspects should be kept in mind when using
computer systems:
— location
— power supply
— temperature, and
— magnetic disturbances.
Fluctuations in the electrical supply can influence computer systems and
power supply failure can result in loss of memory.
3.3 The following general good manufacturing practice (GMP) requirements
are applicable to computer systems.

Verifi cation and revalidation. After a suitable period of running a new
system it should be independently reviewed and compared with the system
specification and functional specifi cation.

Change control. Alterations should only be made in accordance with a
defi ned procedure which should include provision for checking, approving
and implementing the change.

Checks. Data should be checked periodically to confirm that they have
been accurately and reliably transferred.
4. Security
4.1 This is of importance in production as well as in quality control.
4.2 Data should be entered or amended only by persons authorized to
do so. Suitable security systems should be in place to prevent unauthorized
entry or manipulation of data. The activity of entering data, changing or

amending incorrect entries and creating back-ups should all be done in accordance
with written, approved standard operating procedures (SOPs).
4.3 The security procedures should be in writing. Security should also
extend to devices used to store programmes, such as tapes, disks and magnetic
strip cards. Access to these devices should be controlled.
4.4 Traceability is of particular importance and it should be able to identify
the persons who made entries/changes, released material, or performed
other critical steps in manufacture or control.
4.5 The entry of critical data into a computer by an authorized person
(e.g. entry of a master processing formula) requires an independent verifi cation
and release for use by a second authorized person.
4.6 SOPs should be validated for certain systems or processes, e.g. the
procedures to be followed if the system fails or breaks down should be defined
and tested. Alternative arrangements should be made by the validation
team, and a disaster recovery procedure should be available for the systems
that need to be operated in the event of a breakdown.
5.1 Regular back-ups of all files and data should be made and stored in
a secure location to prevent intentional or accidental damage.
6.1 Planning, which should include the validation policy, project plan
and SOPs, is one of the steps in the validation process.
6.2 The computer-related systems and vendors should be defi ned and
the vendor and product should be evaluated. The system should be designed
and constructed, taking into consideration the types, testing and quality assurance
of the software.
6.3 After installation of the system it should be qualifi ed. The extent of
the qualification should depend on the complexity of the system. The system
should be evaluated and performance qualification, change control, maintenance
and calibration, security, contingency planning, SOPs, training, performance
monitoring and periodic re-evaluation should be addressed.
Validation of hardware
and software
Table 1 indicates aspects of computer systems that should be subjected to

Table 1
Summary of validation requirements for computer systems
Hardware Software
1. Types
1.1 Input device
1.2 Output device
1.3 Signal converter
1.4 Central processing unit (CPU)
1.5 Distribution system
1.6 Peripheral devices
1. Level
1.1 Machine language
1.2 Assembly language
1.3 High-level language
1.4 Application language
2. Key aspects
2.1 Location
input devices
2.2 Signal conversion
2.3 I/O operation
2.4 Command overrides
2.5 Maintenance
2. Software identification
2.1 Language
2.2 Name
2.3 Function
2.4 Input
2.5 Output
2.6 Fixed set point
2.7 Variable set point
2.8 Edits
2.9 Input manipulation
2.10 Programme overrides
3. Validation
3.1 Function
3.2 Limits
3.3 Worst case
3.4 Reproducibility/consistency
3.5 Documentation
3.6 Revalidation
3. Key aspects
3.1 Software development
3.2 Software security
4. Validation
4.1 Function
4.2 Worst case
4.3 Repeats
4.4 Documentation
4.5 Revalidation
I/O, Input/output.
7.1 Hardware
7.1.1 As part of the validation process appropriate tests and challenges to
the hardware should be performed.
7.1.2 Static, dust, power-feed voltage fluctuations and electromagnetic
interference could influence the system. The extent of validation should depend
on the complexity of the system. Hardware is considered to be equipment,
and the focus should be on location, maintenance and calibration of
hardware, as well as on validation/qualifi cation.
7.1.3 The validation/qualification of the hardware should prove:

that the capacity of the hardware matches its assigned function (e.g.
foreign language);

that it operates within the operational limits (e.g. memory, connector
ports, input ports);

that it performs acceptably under worst-case conditions (e.g. long hours,
temperature extremes); and

reproducibility/consistency (e.g. by performing at least three runs under
different conditions).
7.1.4 The validation should be done in accordance with written qualifi cation
protocols and the results should be recorded in the qualifi cation reports.
7.1.5 Revalidation should be performed when significant changes are made.
7.1.6 Much of the hardware validation may be performed by the computer
vendor. However, the ultimate responsibility for the suitability of equipment
used remains with the company.
7.1.7 Hardware validation data and protocols should be kept by the company.
When validation information is produced by an outside fi rm, e.g.
computer vendor, the records maintained by the company need not include
all of the voluminous test data; however, such records should be suffi ciently
complete (including general results and protocols) to allow the company
to assess the adequacy of the validation. A mere certifi cation of suitability
from the vendor, for example, will be inadequate.
7.2 Software
7.2.1 Software is the term used to describe the complete set of programmes
used by a computer, and which should be listed in a menu.
7.2.2 Records are considered as software; focus is placed on accuracy,
security, access, retention of records, review, double checks, documentation
and accuracy of reproduction.
Identifi cation
7.2.3 The company should identify the following key computer programmes:
language, name, function (purpose of the programme), input (determine
inputs), output (determine outputs), fixed set point (process variable
that cannot be changed by the operator), variable set point (entered by the
operator), edits (reject input/output that does not conform to limits and minimize
errors, e.g. four- or five-character number entry), input manipulation
(and equations) and programme overrides (e.g. to stop a mixer before time).
7.2.4 The personnel who have the ability and/or are authorized to write,
alter or have access to programmes should be identifi ed.
7.2.5 Software validation should provide assurance that computer programmes
(especially those that control manufacturing and processing) will
consistently perform as they are supposed to, within pre-established limits.

When planning the validation, the following points should be considered.

Function: does the programme match the assigned operational function
(e.g. generate batch documentation, different batches of material used in
a batch listed)?

Worst case: perform validation under different conditions (e.g. speed,
data volume, frequency).

Repeats: sufficient number of times (replicate data entries).

Documentation: protocols and reports.

Revalidation: needed when significant changes are made.

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