ALCOA+ principles of data integrity
Published 15 min read
Fig. 01ALCOA is five words a regulated lab's data has to live up to: attributable, legible, contemporaneous, original and accurate. FDA uses them to define data integrity in its 2018 drug CGMP guidance. ALCOA+ adds four more, complete, consistent, enduring and available, listed by PIC/S in 2021. This guide takes the nine one at a time: the regulator's own words, what each looks like on paper, in a system and in a spreadsheet, and the failure inspectors keep finding.
ALCOA: the five in FDA's 2018 data integrity Q&A
The +: four more in PIC/S PI 041-1 (2021)
Check one record against ALCOA+
Pick a real record, a balance printout, an HPLC result or a logbook line, and walk it through all nine attributes. The record check flags the weak ones and gives the fix for that kind of record.
Who lists ALCOA, and who lists the +
Two documents, two lists. FDA's drug CGMP guidance names five attributes. The PIC/S guide used by GMP and GDP inspectorates repeats those five and lists four more. Most articles blur the two; an inspector's question about your data integrity SOP will not.
FDA, Data Integrity and Compliance With Drug CGMP: Q&A (December 2018), 1.a
“Complete, consistent, and accurate data should be attributable, legible, contemporaneously recorded, original or a true copy, and accurate (ALCOA).”
PIC/S PI 041-1 (1 July 2021), § 7.4
“The following attributes can be added to the list: Complete, Consistent, Enduring and Available (ALCOA+).”
FDA's sentence opens with “complete, consistent, and accurate”, so two of the + words are in its definition of data integrity. They are not on its ALCOA list, and the string “ALCOA+” does not appear anywhere in the Q&A. FDA's footnote 5 then ties each of its five attributes to drug CGMP sections; those cites sit on every card below. The UK's MHRA published its own “Guidance on GxP data integrity” in March 2018 (last updated September 2021), covering GLP, GCP, GMP, GDP and pharmacovigilance.
Common misreading
“ALCOA+ is FDA's standard.” It is not. FDA lists ALCOA, five attributes, in a guidance that contains nonbinding recommendations. The four + attributes are listed in PIC/S PI 041-1 (2021). Cite each list to the body that wrote it, and do not credit “ALCOA++” to any regulator.
Takeaway
In your data integrity SOP, write the five as “ALCOA, FDA guidance (2018)” and the four as “listed in PIC/S PI 041-1 (2021)”. A reviewer who checks the cite finds exactly what you wrote.
The five ALCOA attributes
Each card gives the words the regulator used, the same attribute on paper, in a system and in a spreadsheet, and the failure FDA or PIC/S names. In a system, most of these attributes live in the audit trail. In a spreadsheet they mostly have to be built by hand, which is why Excel spreadsheets under Part 11 need controls a LIMS has by default. Use the switch to read every card in one medium.
Attributable
ALCOA, FDA 2018
“It should be possible to identify the individual or computerised system that performed a recorded task and when the task was performed.”
FDA 2018 Q&A, footnote 5: §§ 211.101(d), 211.122, 211.186, 211.188(b)(11), 212.50(c)(10)
- On paper
- Initials and a date beside every key entry, not one signature at the foot of the page, and a current signature log that ties each set of initials to one person.
- In a system
- One login per person. Every create, change and delete carries the user ID and a computer-generated time stamp in the audit trail, and the administrator is someone who does not own the data.
- In a spreadsheet
- Excel's file properties name the last person who saved the file, not who typed each cell. Attribution has to come from a locked template whose printout the analyst signs and dates, or from moving the calculation into a system with logins.
Classic failure
One shared account on the instrument PC, used by everyone on the shift.
FDA Q&A 5: with shared credentials “a unique individual cannot be identified through the login”. PIC/S § 9.5: shared passwords “should be prohibited”, even to save money.
Legible
ALCOA, FDA 2018
“All records should be legible – the information should be readable and unambiguous in order for it to be understandable and of use.”
FDA 2018 Q&A, footnote 5: §§ 211.180(e), 212.110(b)
- On paper
- A wrong entry is struck through with a single line so the old value stays readable, then initialled, dated and, for critical data, given a reason. No ditto marks, no private abbreviations.
- In a system
- The audit trail shows the old and the new value in words a reviewer can follow, not internal codes, both on screen and on a printout.
- In a spreadsheet
- A printout of values hides formulas, hidden columns and cells typed over. A reviewer who sees only printed numbers cannot tell a calculated value from one keyed in by hand.
Classic failure
Correction fluid, a number written over in place, or a column of ditto marks.
PIC/S § 8.7: the original data must not be “obscured by use of liquid paper; overwriting is not permitted”. § 8.6 names ditto (“) marks as an ambiguous entry.
Contemporaneous
ALCOA, FDA 2018
“The evidence of actions, events or decisions should be recorded as they take place.”
FDA 2018 Q&A, footnote 5: “at the time of performance”: §§ 211.100(b), 211.160(a)
- On paper
- The form is at the bench or on the line when the work happens. PIC/S tells inspectors to check this, because a form kept in an office cannot be filled in at the time.
- In a system
- Data saved at each step, not at the end of a run, against a clock users cannot change and that matches the clocks of connected systems. LIMS and batch record systems can save after every entry.
- In a spreadsheet
- A workbook filled in at the end of the day from notes looks the same as one filled in live, and the PC clock behind its saved time is often one the user can change.
Classic failure
Readings jotted on a glove, a paper towel or a sticky note, copied into the notebook later, then thrown away.
FDA Q&A 12: “It is not acceptable to record data on pieces of paper that will be discarded after the data are transcribed to a permanent laboratory notebook.”
Original
ALCOA, FDA 2018
“The original record can be described as the first-capture of information … Information that is originally captured in a dynamic state should remain available in that state.”
FDA 2018 Q&A, footnote 5: “original or a true copy”: §§ 211.180, 211.194(a)
- On paper
- A balance or pH meter that stores nothing prints the original. The analyst signs and dates it, writes the sample ID or batch number on it, and attaches it to the test record.
- In a system
- The raw data file is the original: the chromatogram or spectrum that can still be reprocessed, with its metadata. The PDF report is a summary of it.
- In a spreadsheet
- When instrument data is exported and pasted into a workbook, the export file is the first capture. Keep it beside the workbook; the workbook is processing, not the original.
Classic failure
Keeping the FT-IR printout and discarding the spectral file.
FDA Q&A 10: the spectral file is dynamic, and a printout “would not satisfy CGMP requirements to retain original records or true copies (§ 211.180(d))”. If the full spectrum is not printed, “contaminants may be excluded.”
Accurate
ALCOA, FDA 2018
“Records need to be a truthful representation of facts to be accurate.”
FDA 2018 Q&A, footnote 5: §§ 211.22(a), 211.68, 211.188, 212.60(g)
- On paper
- Instruments calibrated, critical entries checked by a second person while the work happens, and the record reviewed before release.
- In a system
- Validated for the way you use it, with entry formats the software controls and critical manual entries verified by a second person or by a validated check.
- In a spreadsheet
- FDA calls a spreadsheet dynamic because users can change “formulas or entries in a spreadsheet used to compute test results”. Lock the formula cells, verify the template against a hand calculation, and version it.
Classic failure
Qualifying the platform but never testing the calculation the lab actually runs on it.
FDA Q&A 3: “If you validate the computer system but you do not validate it for its intended use, you cannot know if your workflow runs correctly.”
Fig. 02The four + attributes
The four + attributes are about the record's whole life rather than the moment it is made: whether everything was kept, kept the same way, kept long enough, and can still be found. They are where a paper lab and a validated system differ least, and where a shared drive full of workbooks fails most.
Complete
ALCOA+, PIC/S 2021
“It is important that information is not lost or deleted. … A complete record of data generated electronically includes relevant metadata.”
- On paper
- Bound, page-numbered notebooks; blank fields voided, dated and signed; issued forms counted back in; a spoiled form kept with the reason it was replaced.
- In a system
- Every injection kept, aborted and incomplete ones included, every reprocessing result, and the metadata and audit trail that go with them.
- In a spreadsheet
- Deleting the row of a failing replicate leaves nothing behind, and saving over the file keeps only the latest version.
Classic failure
Saving only the final result of reprocessed chromatography.
FDA Q&A 14 answers “No”. Q&A 13: “All data—including obvious errors and failing, passing, and suspect data—must be in the CGMP records”.
Consistent
ALCOA+, PIC/S 2021
“Information should be created, processed, and stored in a logical manner that has a defined consistency.”
- On paper
- One date format written into the site's procedure (PIC/S gives dd/mm/yyyy or mm/dd/yyyy as examples), a unit on every value, one rounding rule.
- In a system
- Formats enforced by the software, which rejects a value in the wrong format, and time stamps from one synchronised clock, with the time zone recorded where sites span zones.
- In a spreadsheet
- A cell can display 0.10 while it holds 0.0987, and a regional setting can read 03/04 as March or as April. Fix the number format, the rounding function and the date format in the template.
Classic failure
A date like 03/04/2026 that two sites read as two different days, or a global system logging times with no zone.
PIC/S § 8.6: dates in “an unambiguous format defined for the site”. § 9.8: global systems may need “a record of the time zone to demonstrate contemporaneous recording”.
Enduring
ALCOA+, PIC/S 2021
“Records should be kept in a manner such that they exist for the entire period during which they might be needed.”
- On paper
- Indelible ink, never pencil inked over later. Thermal printouts fade, so a signed and dated true copy is made and kept with them.
- In a system
- Backups that are true copies with their metadata, held securely for the whole retention period and proven by restoring them. A copy made in case of a crash is not the backup.
- In a spreadsheet
- A workbook on a laptop or a USB stick is one copy with nothing stopping its deletion. How long it must last comes from the predicate rule; Part 11 sets no period.
Classic failure
A thermal balance strip that has faded blank by the time an investigation asks for it.
PIC/S § 8.6: “some paper printouts from systems may fade over time, e.g. thermal paper. Indelible signed and dated true copies of these should be produced and kept.” FDA Q&A 1.e: temporary crash copies do not satisfy § 211.68(b).
Available
ALCOA+, PIC/S 2021
“Records should be available for review at any time during the required retention period, accessible in a readable format to all applicable personnel who are responsible for their review”
- On paper
- An archive index: which box holds which records, where the box is, how long it is kept, and who may take it out.
- In a system
- Data that still opens after an upgrade or a move to a new system: the old software kept, for example in a virtual machine, or the data migrated under a protocol that checks it all arrived.
- In a spreadsheet
- Files in a personal folder or an inbox leave with the analyst. Keep them where QA and an inspector can reach them, in a format that still opens.
Classic failure
Data that only the superseded software can read, after that software was uninstalled.
PIC/S § 9.4: keeping data readable “may require maintaining access to superseded software”. FDA Q&A 17: FDA may inspect and copy electronic records (§ 211.180(c)).
Takeaway
Read the nine failures again and count how many are settings, not behaviour: shared logins, save-at-end, user-set clocks, overwrite without the old value. Fix those first; they fail every record at once.
Fig. 03Original or true copy
“Original or a true copy” decides more inspection findings than any other letter, because labs print, scan and export all day. FDA's rule of thumb: a printout can be the original when the instrument keeps nothing else, as with a simple balance or pH meter, but not when the data is dynamic and can be reprocessed. A true copy keeps “the content and meaning of the original record”, with all its metadata and its static or dynamic nature (Q&A 9).
Scroll sideways for every column
| Record | The original is | A true copy needs | Where it says so |
|---|---|---|---|
| Balance or pH meter printout (the instrument stores nothing) | The printout itself, signed and dated by the analyst, with the sample ID or batch number written on it. | On thermal paper, an indelible signed and dated true copy kept with the original, because the strip fades. | FDA Q&A 10; PIC/S § 8.9.1, § 8.6 |
| HPLC or FT-IR data (dynamic: it can be reprocessed) | The electronic data file with its metadata, kept so it can still be reprocessed. | An electronic copy that keeps the content, the meaning, all metadata and the dynamic nature. A printout or PDF is not a true copy. | FDA Q&A 1.d, 9, 10 (§ 211.180(d)) |
| Paper record scanned for distribution or storage | The paper. | Checked against the original and signed and dated as a “true copy”, or made by a validated process. Keeping only the scan is possible where the copy was made to aid retention. | PIC/S § 7.7.5 and its true-copy table |
| Electronic record printed to PDF | The record in the system that made it. | Made by electronic file copy with all required metadata. PIC/S says PDF versions “should be prohibited, where there is the potential for loss of metadata”. | PIC/S § 7.7.2, § 7.7.5 |
| Summary report from a contract lab | The data at the contract lab, which you have not seen. | Not a true copy. Rely on it only after assessing the lab's data integrity, with a signed declaration of its accuracy. | PIC/S § 7.8 |
Chromatography is where the dynamic-record rule bites hardest; the chromatography data system comparison reads vendors on reprocessing trails, and the ELN comparison reads notebooks on export and entry locking.
Takeaway
List every instrument in the lab and write down, once, which file or printout is its original record. That list answers half of an inspector's data integrity questions before they are asked.
Where Part 11 carries ALCOA+
21 CFR Part 11 is from 1997 and never uses the word ALCOA. It is written as controls, not attributes. For an electronic record in its scope, though, these controls are where most of the attributes come from. The pairing is our reading; the cites and quotes are the rule's.
- § 11.10(e)
- A computer-generated, time-stamped audit trail of operator entries and actions; “Record changes shall not obscure previously recorded information.” Carries: Attributable, contemporaneous, legible
- § 11.10(d), (g)
- Access limited to authorised people, and authority checks on who may sign or alter a record. Carries: Attributable
- § 11.50, § 11.70
- A signature shows the printed name, date and time, and meaning, and stays linked to its record. Carries: Attributable
- § 11.10(a)
- Validation for “accuracy, reliability, consistent intended performance”. Carries: Accurate
- § 11.10(b)
- “accurate and complete copies of records in both human readable and electronic form” for FDA. Carries: Original or true copy, complete, available
- § 11.10(c)
- “accurate and ready retrieval throughout the records retention period”. Carries: Enduring, available
Consistent has no Part 11 control of its own; it comes from your procedures and the formats your system enforces. Each section is explained in 21 CFR Part 11 requirements, section by section, and the EU's computerised systems annex is covered in the guide to EU Annex 11. Tools built around locked records, edit trails and review are compared in data integrity software for GxP labs.
Takeaway
Before you buy or validate a system, test the attributes, not the brochure: make one change and read the trail, export one record and open the copy, restore one backup. Then check one record against ALCOA+ with the record check, and plan the trail review with the audit trail review checklist.
ALCOA+ on one sheet
- Attributable
- One login per person; initials and date on every key entry. (FDA Q&A 5, PIC/S § 9.5)
- Legible
- Single-line corrections, old value readable, reason for critical changes. (PIC/S § 8.7)
- Contemporaneous
- Forms at the point of use; data saved at each step, against a clock users cannot change. (FDA Q&A 12)
- Original
- Keep the first capture in its own form: the printout, or the raw data file. (FDA Q&A 10)
- Accurate
- Calibrated instruments, second-person checks, calculations validated as used. (FDA Q&A 3)
- Complete
- Every result kept, failing and aborted ones too, with metadata. (FDA Q&A 13, 14)
- Consistent
- One date format, units on values, one rounding rule, written in the SOP. (PIC/S § 8.6)
- Enduring
- Indelible ink; true copies of thermal paper; backups proven by restore. (PIC/S § 8.6, FDA Q&A 1.e)
- Available
- An archive index, readable formats, old software kept or data migrated and checked. (PIC/S § 8.10, § 9.4)
Questions
Is ALCOA+ an FDA requirement?
FDA does not use the term. Its 2018 Q&A defines data integrity with the five ALCOA attributes, and it is a guidance that “Contains Nonbinding Recommendations”. The duties behind each attribute come from the CGMP rules its footnote 5 lists. The four + attributes are listed in PIC/S PI 041-1. Their ideas are still in US rules: § 211.194 asks for “complete data derived from all tests”, and § 211.180 sets how long records are kept.
What is ALCOA++?
You will see it in training material and vendor articles, usually with one or more extra attributes. Neither FDA's 2018 Q&A nor PIC/S PI 041-1 uses it, and we have not read it in a regulator's text, so we do not credit it to any body. If your SOP uses a longer list, name the source that wrote it.
Does ALCOA apply to paper records?
Yes. PIC/S says the principles “are applicable to both” paper and electronic records, and § 8.1.2 asks that paper records stay ALCOA+ “throughout the data lifecycle”. FDA's Q&A 2 says paper and electronic record-keeping systems “are subject to the same requirements”.
How soon is contemporaneous?
Neither text gives minutes. PIC/S says “as they take place”; FDA says “at the time of performance”. PIC/S § 9.6 gives the test for systems: if the order of four raw-material additions is a critical process parameter, each addition gets its own time stamp; one entry for all four is acceptable only when the order does not matter.
Where did the four + attributes come from?
PIC/S PI 041-1 § 7.4 lists them and footnotes the list to “EMA guidance for GCP inspections conducted in the context of the Centralised Procedure”. FDA's 2018 Q&A, written for drug CGMP, keeps to the five.
Where does MHRA's guidance fit?
The UK regulator published “Guidance on GxP data integrity” on 9 March 2018 and last updated it on 27 September 2021. It covers GLP, GCP, GMP, GDP and pharmacovigilance for organisations MHRA regulates; for UK GLP, the OECD advisory document on data integrity (20 September 2021) takes precedence. A US lab that only answers to FDA reads it for background, not as a rule.
Sources
Attribute meanings quoted from PIC/S PI 041-1 § 7.5; FDA's list and examples from its 2018 Q&A; regulation text from the eCFR. General information, not regulatory advice.
- Data Integrity and Compliance With Drug CGMP: Questions and Answers (December 2018), Q&A 1–17 and footnote 5, FDAread 2026-10-22
- PI 041-1, Good Practices for Data Management and Integrity in Regulated GMP/GDP Environments (1 July 2021), §§ 7.4–7.8, 8.6–8.10, 9.4–9.8, PIC/Sread 2026-10-22
- Guidance on GxP data integrity (published 9 March 2018, updated 27 September 2021), MHRA, GOV.UKread 2026-10-22
- 21 CFR Part 11, Electronic Records; Electronic Signatures, § 11.10, § 11.50 (eCFR, up to date as of 2026-10-20), eCFRread 2026-10-22
- 21 CFR Part 211, CGMP for Finished Pharmaceuticals, § 211.68, § 211.180, § 211.194, eCFRread 2026-10-22