First Pass Yield Improvements on routers 760B. Define Phase

[Pages:16]Define Phase SSP #1/3 - Project Charter:

First Pass Yield Improvements on routers 760B. TEPM 6304 Six Sigma Green Belt Project

Date:

Project Title:

Project Leader:

Champion:

Company / Department Description:

09/22/09

First Pass Yield Improvements on routers 760B.

Yugo Morita

Router Business Unit CFT Manager

Foxconn is a Contract Manufacturing for HAWK Systems and its operations at the Houston facility employees approximately 350 employees. The operation is divided into different business units (BUs) with a dedicated Customer Focus Team (CFT) for each BU.

The router 760B belongs to the Router BU. This router is manufactured along an assembly line process consisting of seven to eight stations connected by a conveyor. Each station has a specific task/procedure to install up to 4 different components on each unit and then pass the unit to the next station.

Team Member Yugo Morita Surapheal Belay Gregory Strube Rajani Matti Elizabeth M. Problem Statement:

Mission Statement: Stakeholders:

After the final check (last station) every unit is tested on a station (Final System Test - FST) which checks the unit's configuration. Then the software is then loaded into the router's system.

Function

% Time

Initials

Project Leader

20

YM

Process Engineer

20

SB

Program Management

20

GS

Program Management

20

RM

Process Engineer

20

EM

The 760B routers have averaged only 97.77% first pass yield (FPY) (i.e., the lowest among all platforms in the router business unit) i.e., the lowest among all platforms in the router business unit in the past 8 months (2/09-9/09), resulting in a loss in revenue.

Increase the FPY for the router 760B to 98.5% or better in the next 4 months (by 1/10) resulting in $41,136.00/month in new revenue.

Router CFT Manager: Improve FPY (First Pass Yield) as a rework reduction and cycle time gains on Router BU. Quality Manager: Ensure that the outstanding failures are addressed properly. Collect and share best practices across all Foxconn sites. HAWK Systems: better visibility on manufacturing process as well as involvement on quality/productivity related issues. Repair Technicians: Reduction on workload and reduction on repetitive failures

SSP #2/3 - SIPOC Diagram:

Suppliers

Input

Process

Outputs

Internal and external vendors

Raw materials

Install mother board (Printed Circuit Board Assembly PCBA)

FST Report with detailed Swap Log

Hawk Systems Telecom

Test scripts

Install memory (CF/DRAM) and processors cards

Router Operational System Software (IOS)

Install power supply (PS) and cables

Customers Hawk Systems

Router management team

Install modules (NM) and interface cards (WIC)

Install Blanks

Cover up chassis

Test Set Up

Test ? Components check, Load Software and functionality test

Troubleshoot failed unit

Assembly Operators

SSP #2/3 - Flowchart:

The flowchart below shows the steps needed to assemble the router done by Line Operators prior to test it at FST (Final System Test) station on which the Repair Technicians are responsible to troubleshoot the failed unit and then investigate what caused the failure.

START

Install PCBA and scan serial

number into AT database

Screw in Blanks on empty slots

I ns ta l l CF/DRAM/PVDM and scan serial number into AT

Cover up chassis/unit

Install PS and scan serial number

into AT database

Plug in connectivity

cables

Install Modules and WICs. Scan serial number into AT database

Load the unit into test rack

Plug in console, ethernet and power cables

Scan Traveler's info / Start the test

Does router Yes

pass?

No

Rework failed unit

- swap components - install correctly

(*) Auto Test Environment

Unplug all cables and pass the unit to the next station

END

PCBA - Printed Circuit Board Assembly (motherboard) AT - Auto Test database where is recorded PCBA's serial number as well as it's test records. CF - Compact Flash. Storage device that works as hard drive. DRAM - Dynamic Randon Access Memory. PVDM - Packet Voice DSP Module Traveler - Document that contains the order details (unit configuration) (*) Auto Test Environment - See Measurement System Flowchart for details.

Repair Technicians

Other Tools:

The project metric can be defined as monitoring the FPY ? First Pass Yield indicator given by the Auto Test station. The process is measured by the quantity of units that is tested and passed all test steps on first try without any failures caused by either related with assembly process (operator induced failures), hardware failures or test script related issues. Below is the FPY trend chart comparing routers 760B with overall routers assembled and tested on Router BU.

VOICE OF THE CUSTOMER (VOC)

Increase Routers 760A and 760B capacity

CRITICAL TO QUALITY (CTQ)

First Pass Yield above 98% "Build it correctly the first

time" approach

PROJECT METRIC (Y)

Quantity of units passed the test for the first time.

First Pass Yield Trend Chart for Overall Routers

The overall (all routers platforms) First Pass Yield is averaging 98.42% and consistently above the threshold set as 98.00% which is the desired trend expected for all routers produced on this business unit. First Pass Yield Trend Chart for 760B Routers

Above FPY trend chart for 760B routers shows that it's trend makes a significant impact on overall trend as when the low yield on this routers drags down significantly the overall FPY Among Router products, 760B platforms have the most unstable FPY compared with other platforms. Due to its assembly complexity and unstable PFY, the 760B platforms will be prioritized with actions on both major and common failures in order to increase the overall FPY.

Measure Phase

SSP #4 ? Measurement System Flowchart:

The Auto Test environment is comprised of devices such as switches, power box computer and cables that connect each tested unit to HAWK System database. After the router is connected to test cells, the Auto Test System begins testing the router and this test can be breakdown in three major steps: Diagnostic Test, Load IOS software test and Functional test.

Each test is specific for each platform/order configuration which the test script determines the sequence of verification/commands to be done on the router. In case of any abnormal situation (such as wrong component, wrong installation, hardware defects or network connectivity issues) the Repair Technicians must troubleshoot the failed unit and then investigate the issue.

Based on which step the unit failed, the Auto Test system gi ves the failure symptom as well as the indication on which step this failed. This way, the Repair Technician are able to narrow down the trouble shoot and focus on a specific component and report their findings.

Note: Test script related failures will be disregarded from this analysis because the database is owned by our customer Hawk Systems and our engineers do not have any control of script corrections or adjustments.

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