The acronym ALCOA is used by regulated industries as a framework for ensuring data integrity, and is key to Good Documentation Practice (GDP). ALCOA relates to data, whether paper or electronic, and is defined by US FDA guidance as Attributable, Legible, Contemporaneous, Original, and Accurate. These simple principles should be part of your data life cycle, GDP, and data integrity initiatives.


All data generated or collected must be attributable to the person generating the data. This should include who performed an action and when. This can be recorded manually by initialing and dating a paper record or by audit trail in an electronic system.

For example:

During a validation exercise, test results should be initialled and dated by the person executing the test. Adjustment of a set point on a process or monitoring system should be made by an authorized user and the details of the change logged in an audit trail. A correction on a lab record should be initialled and dated to show when and who made the adjustment.

Note: It is important to ensure a signature log is maintained to identify the signatures, initials and/or aliases of people completing paper records.


All data recorded must be legible (readable) and permanent. Ensuring records are readable and permanent assists with its accessibility throughout the data life cycle. This includes the storage of human-readable metadata that may be recorded to support an electronic record.

For example:

GDP will always promote the use of indelible ink when completing records. When making corrections to a record, ensure a single line is used to strike out the old record. This ensures the record is still legible. Controlling your paper records/forms and formatting them such that there is ample room for the information to be recorded.


Contemporaneous means to record the result, measurement, or data at the time the work is performed. Date and time stamps should flow in order of execution for the data to be credible. Data should never be back dated.

For example:

If executing a validation protocol, tests should be performed and their results recorded as they happen on the approved protocol. Data that is logged, or testing that is performed electronically, should have a date/time stamp attached to the record. Ensure electronic systems that log data have their system clocks synchronized. Consider the use of a master clock system that synchronizes to the IT network so wall clocks within labs and processing areas are synchronized .


Original data, sometimes referred to as source data or primary data, is the medium in which the data point is recorded for the first time. This could be a database, an approved protocol or form, or a dedicated notebook. It is important to understand where your original data will be generated so that its content and meaning are preserved.

For example:

Ensure validation test results are recorded on the approved protocol. Recording results in a notebook for transcription later can introduce errors. If your original data is hand written and needs to be stored electronically, ensure a “true copy” is generated, the copy is verified for completeness and then migrated into the electronic system.


For data and records to be accurate, they should be free from errors, complete, truthful, and reflective of the observation. Editing should not be performed without documenting and annotating the amendments.

For example:

Use a witness check for critical record collection to confirm accuracy of data. Consider how to capture data electronically and verify its accuracy. Build accuracy checks into the design of the electronic system. Place controls/verification on manual data entry, for example, temperature results can only be entered within a predefined range of 0-100°C.


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