Overview of the DAME Project Distributed Aircraft Maintenance Environment University of York Martyn Fletcher

Project Goal Build a GRID Application for Distributed Diagnostics. Application is generic, but application demonstrator will be for aircraft maintenance. Three year project - began in January One of six pilot projects funded by the EPSRC under the current UK e-Science initiative.

Outline Of Basic Operation On landing – DAME receives data from the engine. DAME looks for patterns, performs modelling etc. and provides a diagnosis / prognosis. DAME system made up of GRID based web services. DAME system also provides analysis tools etc. for use by Domain Experts etc.

Benefits of Use Allows problems to be detected early and common causes to be detected. Ultimately will reduce flight delays, in-flight shutdowns and aborted take- offs - due to engine problems.

DAME Collaborators University of York. University of Leeds. University of Oxford. University of Sheffield. Rolls-Royce Plc. (RR). Data Systems & Solutions LLC. (DS&S). Cybula Ltd.

Technologies Used AURA - Advanced Uncertain Reasoning Architecture – high performance pattern matcher developed by University of York and Cybula Ltd. QUOTE – “On The Engine” - intelligent engine signature collection / local diagnosis system developed by University of Oxford for Rolls Royce / DS&S. Decision Support – University of Sheffield. GRID architecture / web services – University of Leeds.

Current Work Developing expertise in GRID architectures and web services. Developing AURA to make it available as a GRID web service. QUOTE work is ongoing. Developing Decision Support. Working with the “users” RR and DS&S to develop the use cases (following slides).

Use Case Process 1. Define the DAME system scope and boundaries. 2. Identify the list of primary actors. 3. Identify the list of primary actor goals / use cases for the DAME system. 4. Describe the outermost (overall) summary use cases. 5. Revise the outermost summary use cases. 6. Expand each DAME system use cases. 7. Reconsider and readjust the set of uses cases.

Primary Actors Maintenance team Engine releaser Maintenance scheduler Maintenance advisor Domain expert MR&O engine releaser MR&O Condition Recorder Knowledge engineer System administrator

Outermost Use Cases Release Engine. Dispossess the QUOTE anomaly. Plan Maintenance Schedule. Provide Maintenance Advice. Provide Maintenance Information. Provide Expert Information. Pass-Off Engine. Capture Knowledge. Maintain the System.

DAME Use Cases Perform Diagnosis. Perform Analysis. Model The System. Match The Pattern. Provide The Decision. Update Local Diagnostics. Provide Statistics Report Etc.

DAME Use Case Diagram

Use Case – Perform Diagnosis (Main Success Scenario) 1. The DAME system analyses the data using e.g. Match the Pattern, Model the System use cases, etc. 2. The DAME system assesses the results and determines the diagnoses / prognoses and confidence levels. 3. The Domain Expert (DE) receives the proposed diagnosis / prognosis. 4. The DE accepts it. 5. The DE provides the result to the Maintenance Team.

Use Case – Perform Diagnosis (Extensions) 4a. The Domain Expert does not accept the diagnosis / prognosis: requests more information from the Maintenance Team and / or Performs Analysis. Continues at step 5.

Future Use Case (UC) Work. Expand existing UCs in discussion with the users - RR and DS&S. Use these in planning the DAME demonstrations. Update UCs as project progresses. Consider other domains e.g. medical.

Use Case Conclusions. Use case diagrams –Tend to confuse people. –Useful as an overview only. Use cases in text form –Easily understood. –Users like them. –Very little jargon. Key point - know when to stop expansion of use cases. FOR MORE INFO...