Personnel statistics are derived from the Ministry of Defence’s Joint Personnel Administration (JPA) system. This is used for the administration of all armed forces personnel.
Extracts are taken from the JPA system each quarter and stored on a separate database to form a time series. The extracts are taken 6 days after the end of the month and calculate the situation as at the 1st of the month. This means that the statistics include data that may have been submitted to the JPA a few days late. However, some late reporting can affect the statistics – for example, when someone leaves or their status changes from untrained to trained.
The data goes through a series of automatic validation checks based on previous corrections. As a result of these checks, edits are made to the data to ensure basic data quality.
Once the data is confirmed as being accurate, the database is queried to produce the range of tables. These tables undergo several rounds of checking and scrutiny to ensure the outputs are accurate and consistent, before being published.
All personnel in the regular armed forces must be recorded on the JPA system for them to receive their pay. Therefore, the overall workforce figures are accurate. However, more detailed breakdowns can be less accurate, because some key information required for categorising individuals is recorded and updated centrally, whereas other information is added by individuals themselves.
Suppression rules and disclosure control
Data identifying fewer than 6 people is suppressed to protect confidentiality.
In the charts, tables and commentary, percentages have been rounded to 1 decimal place.
In the data download, counts are rounded to the nearest 10. However, numbers ending in 5 have been rounded to the nearest multiple of 20 to prevent the systematic bias caused by always rounding numbers upwards. For example, a value of 25 would be rounded down to 20 and a value of 15 would be rounded up to 20.
Totals and subtotals are rounded separately, so may not equal the sums of their rounded parts.Quality and methodology information