What is the Defence Lessons Identified Management System (DLIMS)?


The Defence Lessons Identified Management System (DLIMS) is a UK Defence-wide database to deal with the collection, management, and distribution of lessons. It is a tool that enables the Chain of Command to allocate responsibilities, track actions, and archive work on each issue but individual Defence Organisations have also developed their own databases, in some cases building on existing capabilities to exploit interrogation tools. As of February 2020, work commissioned by D HS&EP was underway to understand the totality of the data available, improve Information Management, and improve the utility and usage of DLIMS.

Royal Navy

Accident/incident specific lessons are captured on the Navy Lessons Information Management System (NLIMS), which can be accessed by all Navy Command domains and external stakeholders under licence. NLIMS has linkage with DLIMS so that data can be shared with other parts of the Ministry of Defence (MOD). In addition, Defence Statistics can directly access NLIMS to gather Navy Command accident and incident data. Dissemination of lessons is through the NLIMS system, safety focal points, and safety advisors within the chain of command and their regular safety meetings.

All events captured in NLIMS are scrutinised and investigated appropriately. Lessons are learned through the allocation of remedial actions such as a revision or more substantive change of guidance and policy. Significant events are investigated through an SI or Fleet Commander’s Safety Investigation. Recommendations from these are captured and monitored under the Recommendation Implementation Tracker managed by the Navy Safety Centre with progress to completion reported at the Maritime Safety Board chaired by the Fleet Commander.

Navy Command, through the Navy Safety Centre, has initiated further work to learn lessons from both leading (audit reports) and lagging (event reports and investigations) indicators using data analytic programmes. This data will be presented via a common dashboard that can be used at different management levels within the Top Level Budget (TLB).


The Army’s Lessons Process (ACSO 1118) is the framework used for capturing, analysing, resolving, and exploiting lessons at Unit, Formation, and Army-wide level. The process spans all activity areas (Operational, Training, and Safety, Health & Personnel) and is overseen by the Deputy Chief of the General Staff (DCGS). Chief Safety (Army) is responsible for ensuring coherence across the Safety/Personnel/Health domains.

All significant incidents are investigated in accordance with this process. In the safety environment, this results in either an Army SI or Unit investigation/Learning Account. The most serious safety incidents (death, serious injury, or loss of major capability) are investigated by DSA/Defence Accident Investigation Branch as a Defence level investigation. Investigations result in recommendations to prevent a recurrence, which are rigorously pursued until resolution is understood. The Army Safety Centre is responsible for safety specific lessons (utilising DLIMS) and addressing systemic issues with stakeholders in the Army and the wider MOD.

As part of wider organisational learning, the Army Lessons Process promotes learning by all and specifically directs lessons activity across 12 functional areas. Each functional area has an assigned lead empowered to deliver lessons management and seek resolution within their areas of responsibility. Military Judgement Panels for each functional area are convened to consider unresolvable lessons that may arise, elevating through Integration Groups (for wider coherence) to the Army Lessons Steering Group as required. The overall Army Lessons Process is governed by the 3* Army Executive Committee and undergoes periodic reviews to ensure that it is fully embedded throughout the chain of command.

Once investigated, lessons are communicated formally through chain of command cascade notices and Army Briefing Notes. Additional pathways for safety notices to reach users include Army Safety & Environment Matters magazine and the quarterly equipment related KiT! Magazine.

Royal Air Force

The Air Lessons Process is the mechanism for capture, analysis, resolution, and dissemination of lessons in the RAF. Lessons are identified during daily activity across the full remit of Service activity and stored on DLIMS for resolution. For specific events or incidents (eg exercises, short-notice and/or contingent operations, Squadron operational handovers etc.) a unique, targeted, lessons trawl is initiated and disseminated through the RAF’s network of trained Lessons personnel (currently more than 55 individuals). This ensures maximum coverage across the RAF; lessons can be identified and captured from diverse business activities not conventionally considered as part of the activity in question, thereby enhancing perspective and increasing the knowledge extrapolated from each lesson.

Upon completion of a lessons capture trawl, a Military Judgement Panel of experienced personnel reviews all the returns to remove duplication, refine the core lesson points, and provisionally assign ownership for resolution. Lessons personnel from across the RAF participate in this process, speeding up acceptance of the outcome(s). Lessons are then disseminated via DLIMS to the agreed owner and the resolution process takes place through a network of supporting action managers. Their responses are recorded under the lesson entry on DLIMS, building up an evidence chain that eventually leads to the successful resolution of that lesson and its closure. Should a lesson not be resolvable in a reasonable timescale (due to finance, resource, or contractual issues etc) then it is closed and reviewed annually, with a risk being raised via HQ Air Command’s SAPPHIRE risk reporting system.

Thematic Analysis is conducted, with key findings discussed in an After-Action Review, chaired by an officer of appropriate rank, and publicised for wider awareness.

Lessons are considered to have been learned upon completion of the Air Lessons Process. The lesson, and its associated evidence chain, are stored in perpetuity on DLIMS and are accessible to all across Defence. When planning an event, DLIMS is reviewed for any pertinent points, ensuring the knowledge learned informs planning from the outset. In addition, any additional Thematic Analysis documents, previous Post Operation/Exercise Reports and any associated debrief materials are reviewed. All materials generated via the Air Lessons Process are passed to the RAF’s Lessons personnel for onward dissemination and are published on the Organisational Learning and Lessons web page.

The RAF Safety Centre Promotion team collates pertinent identified lessons for use in the promotion of enhanced safety processes to prevent recurrence. Subject Matter Experts regularly contribute articles to ‘AirClues’ (the Total Safety magazine for the RAF) and these include advice on Heat illness/Cold injuries, the responsibilities of Commanders, Heads of Establishment, and Duty Holders, and lessons learned from previous occurrences.

Specialist Military Units

SMUs use both NLIMS and DLIMS to record and share lessons internally and with wider Defence so lessons can be disseminated and learned by all relevant personnel. A monthly lessons stock take has previously taken place with oversight at senior level. Lessons are also fed into, and taken from, monthly Military Judgement Panels chaired by Deputy Director SMU.


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