Reproduction interdite © ALMA EUROPEAN CONSORTIUM Reproduction forbidden Design, Manufacture, Transport and Integration in Chile of ALMA Antennas Page 1 Design, Manufacture, Transport and Integration on-site in Chile of ALMA Antennas RAMS ANALYSIS PM# February 2006

Reproduction interdite © ALMA EUROPEAN CONSORTIUM Reproduction forbidden Design, Manufacture, Transport and Integration in Chile of ALMA Antennas Page 2 SUMMARY Alcatel Alenia Space Italia will be responsible for the execution of the RAMS analysis for the whole antenna. Within this responsibility AASI will perform: the hazard analysis to identify all potential hazards related to the design, the operation and the maintenance of the antenna and define the measures needed to remove or bring them to an acceptable level. The safety compliance assessment documenting the compliance with the ALMA safety requirements. The RAM analysis in order to contribute in the definition of antenna architecture, related maintenance approach and the related spare philosophy

Reproduction interdite © ALMA EUROPEAN CONSORTIUM Reproduction forbidden Design, Manufacture, Transport and Integration in Chile of ALMA Antennas Page 3 SAFETY ACTIVITY Hazard Analysis Using the definition of Hazard categories (I ÷ IV), probability level (A ÷ E), hazard classification and acceptability matrices from Technical Specification, scope of the safety analysis is: Definition of the Hazard list showing: Hazard Effect Cause Hazard Analysis defining for each identified hazard: Means for prevention Hazard Category Probability level Risk index ( combination of category and probability) Actions to be undertaken. Hazard register to trace and document the implementation of the defined actions

Reproduction interdite © ALMA EUROPEAN CONSORTIUM Reproduction forbidden Design, Manufacture, Transport and Integration in Chile of ALMA Antennas Page 4 SAFETY ACTIVITY Safety compliance Safety compliance will consider the collection of the entire safety related documentation relevant to the antenna project in accordance with the safety requirements of the ALMA technical specification. The assessment will be documented in the Safety Compliance Assessment Report where evidence will be provided of compliance status with the safety design requirements together with the design, test,inspection and special procedures information. The conclusive statement of conformity will be included

Reproduction interdite © ALMA EUROPEAN CONSORTIUM Reproduction forbidden Design, Manufacture, Transport and Integration in Chile of ALMA Antennas Page 5 SAFETY ACTIVITY OUTPUTS Hazard analysis report in accordance with DRD-28 Safety Compliance assessment in accordance with DRD-29

Reproduction interdite © ALMA EUROPEAN CONSORTIUM Reproduction forbidden Design, Manufacture, Transport and Integration in Chile of ALMA Antennas Page 6 RAM ACTIVITY The Mean Time Between Failure (MTBF) of the antenna under the specified operational conditions will be calculated starting from the system modelization (in term of Reliability Block Diagram) and the equipment failure rate. The failure rate of each equipment is either provided by the supplier or calculated on the basis of available information. Typical reference sources are: Parts Count Method as per MIL-HDBK-217F + Notice 2 (electronic-electrical components). NPDR-95 of the US department of defence (for non electronic parts) RDF 2000 (for electronic components). The duty cycle of each part will be considered according to the specified antenna operational profiles.

Reproduction interdite © ALMA EUROPEAN CONSORTIUM Reproduction forbidden Design, Manufacture, Transport and Integration in Chile of ALMA Antennas Page 7 RAM ACTIVITY The RAM analysis (for MTBF evaluation) will be developed, using a dedicated Reliability/Availability model that includes only the intrinsic Antenna equipment characteristics (e.g. failure rates, MTTR(s), preventive maintenance time intervals, etc.) excluding any logistic constraint not under AEM visibility/responsibility. This approach is in line with the content of para. 8.1 in the technical specification. The spare strategy will be identified using models generally adopted in the common practice (e.g. Poisson approach). A dedicated analysis will be performed to estimate the expected time spent in corrective and preventive maintenance, given in terms of man-hours/month.

Reproduction interdite © ALMA EUROPEAN CONSORTIUM Reproduction forbidden Design, Manufacture, Transport and Integration in Chile of ALMA Antennas Page 8 RAM ACTIVITY OUTPUTS Spare part list in accordance with DRD-35 Reliability Availability Analysis in accordance with DRD-25

Reproduction interdite © ALMA EUROPEAN CONSORTIUM Reproduction forbidden Design, Manufacture, Transport and Integration in Chile of ALMA Antennas Page 9 REMARKS Some clarifications of Technical Specification requirements are needed: Table refers to the system out of operation for more (less) than 3 months: This is understood being applicable to the single antenna: pleas confirm. Tables to : according to this approach some failure events (with impact only on antenna operation) could be not acceptable (e.g. marginal III A) while they are perfectly acceptable from MTBF requirement point of view. Para 9.1.5: This para does not include any requirement but only identification of possible failure rates data sources. In case the MIL-HDBK-217F is adopted for some equipment the reference operative environment should be G M (Ground Mobile) instead of A UC (Airborne Uninhabited Cargo)