Technical Communications Practicum: Failure Modes, Effects and Criticality Analysis SmartShopper Jeff Richards, John Sweeney, Stevi Wood and Tera Wong

Primary Subsystems Voltage Switching Regulator RFID Reader USB Module Microcontroller Digital Compass LCD

Voltage Switching Regulator and Circuitry A

RFID Reader Connectors and Supporting Circuitry B

Failure No. Failure ModePossible CausesFailure EffectsMethod of Detection CriticalityRemarks B1No input Faulty wire connection to header; Faulty RFID module; Failure of U 6 Unable to locate specific items on shopping list, which was input by customer ObservationLow The RFID tags are not located throughout the store. Microcontroller receives no data. B2Incorrect output Faulty wire connection to header; Faulty RFID module; Failure of U 6, C 20, C 17, C 16, C 18, C 19 Items on shopping list not found or wrong item indicated as found ObservationLow The wrong RFID could be passed to the microcontroller

USB Controller and Connector C

Failure No. Failure ModePossible CausesFailure EffectsMethod of Detection CriticalityRemarks C1 No input from USB memory stick Faulty USB connector; Failure of Y 1, R 1, R 2, C 3, C 4, C 5 Shopping list is not loaded ObservationLow C2 Incorrect input voltage level Failure of C 2, C 1, C 5, U 4 Shopping list is not loaded ObservationLow

Microcontroller D

Failure No. Failure ModePossible CausesFailure EffectsMethod of Detection CriticalityRemarks D1Incorrect output Failure of internal microcontroller circuitry, software Jumbled LCD display ObservationLow D2 Constant output value Failure of Y 6, C 14, C 15 Unchanging LCD display ObservationLow D3 No output to LCD display Failure of I/O pinsNothing on LCDObservationLow D4 No power or incorrect input voltage levels Failure of U 4, bypass capacitor Nothing on LCDObservationLow D5 Reset signal flickering Failure of R 12, CW 3, software Intermittent display on LCD ObservationLow

Digital Compass Connector E

Failure No. Failure ModePossible CausesFailure EffectsMethod of Detection CriticalityRemarks E1No output Faulty wire connection to header Instructions are not updated automatically ObservationLow The user will have to push a button for the next instruction. E2Incorrect outputOut of calibration Instructions are not updated at appropriate time or not at all ObservationLow The user will have to push a button for the next instruction. And product might possibly give incorrect instructions.

LCD Connectors and Supporting Circuitry F

Failure No. Failure ModePossible CausesFailure EffectsMethod of Detection CriticalityRemarks F1 No characters on LCD Faulty I/O connection; Faulty LCD; Failure of U 3, U 6,, C 20, C 17, C 16, C 18, C 19 Impossible to see/read the directions being given. ObservationLow F2 Invalid characters on LCD Faulty I/O connection; Faulty LCD; Failure of U 3, U 6, C 17, C 16, C 18, C 19 Impossible to comprehend the directions being given. ObservationLow