Weibull++ Example 6 - Factory Equipment Failure Log
Background
A manufacturer is tracking the failures occurring in the product line. When a failure occurs in a machine, the time of occurrence and the time of repair are recorded for the machine and the parts that failed. Using Weibull++’s Event Log, determine the failure and repair distributions.
Experiment and Data
The machines operate 8 a.m. to 5 p.m. Monday through Friday. The time of occurrence and time of repair for the machine and parts that failed are shown in the following table.
| Machine |
Failure/ Event |
System Failed | System Restored | Part Responsible | |||
| Date | Time | Date | Time | Component | Sub-Component | ||
| 1 | F | 3/1/04 | 11:00 AM | 3/5/04 | 9:00 AM | Electric Saw | Motor |
| 1 | F | 4/1/04 | 2:30 PM | 4/3/04 | 11:00 AM | Conveyer | Belt |
| 1 | E | 5/3/04 | 9:00 AM | 5/6/04 | 12:00 PM | Lubrication | Lubrication |
| 1 | F | 8/3/04 | 3:30 PM | 8/4/04 | 9:00 AM | Electric Saw | Blade |
| 1 | E | 9/1/04 | 4:10 PM | 9/2/04 | 4:00 PM | Inspections | Inspections |
| 1 | F | 12/1/04 | 10:00 AM | 12/2/04 | 3:00 PM | Conveyer | Wheels |
| 1 | F | 1/4/05 | 12:30 PM | 1/7/05 | 7:20 AM | Hydraulic Arm | Hydraulic Lines |
| 1 | F | 2/1/05 | 4:00 PM | 2/2/05 | 7:00 AM | Hydraulic Arm | Piston |
| 1 | F | 3/7/05 | 4:15 PM | 3/9/05 | 9:00 AM | Conveyer | Belt |
| 1 | F | 4/5/05 | 4:30 PM | 4/6/05 | 4:45 AM | Electric Saw | Blade |
| 1 | F | 5/9/05 | 3:00 PM | 5/11/05 | 10:00 AM | Hydraulic Arm | Motor |
| 1 | F | 5/18/05 | 2:00 PM | 5/19/05 | 12:30 PM | Hydraulic Arm | Hydraulic Lines |
| 1 | F | 6/2/05 | 1:00 PM | 6/3/05 | 3:00 AM | Electric Saw | Blade |
| 1 | F | 6/20/05 | 11:00 AM | 6/22/05 | 2:15 AM | Hydraulic Arm | Hydraulic Lines |
| 2 | F | 2/4/04 | 9:00 AM | 2/5/04 | 9:00 AM | Hydraulic Arm | Piston |
| 2 | F | 3/8/04 | 9:00 AM | 3/9/04 | 11:00 AM | Electric Saw | Motor |
| 2 | F | 4/5/04 | 11:00 AM | 4/6/04 | 10:00 AM | Hydraulic Arm | Arm |
| 2 | F | 4/14/04 | 2:00 PM | 4/16/04 | 2:30 AM | Hydraulic Arm | Hydraulic Lines |
| 2 | F | 6/7/04 | 1:00 PM | 6/9/04 | 2:00 AM | Hydraulic Arm | Piston |
| 2 | F | 7/23/04 | 4:15 PM | 7/25/04 | 3:15 AM | Electric Saw | Motor |
| 2 | F | 8/23/04 | 3:00 PM | 8/25/04 | 3:30 AM | Conveyer | Belt |
| 2 | E | 9/27/04 | 9:20 AM | 9/27/04 | 3:15 PM | Cleaning | Cleaning |
| 2 | F | 11/8/04 | 11:00 AM | 11/9/04 | 9:15 AM | Hydraulic Arm | Motor |
| 2 | F | 1/25/05 | 10:00 AM | 1/26/05 | 2:45 AM | Electric Saw | Blade |
| 2 | F | 2/3/05 | 10:00 AM | 2/3/05 | 3:20 PM | Conveyer | Wheels |
| 2 | F | 3/23/05 | 12:00 PM | 3/25/05 | 4:00 AM | Conveyer | Belt |
| 2 | E | 3/28/05 | 10:45 AM | 3/29/05 | 12:00 PM | Lubrication | Lubrication |
| 2 | F | 5/10/05 | 3:00 PM | 5/11/05 | 10:15 AM | Electric Saw | Motor |
| 2 | E | 5/23/05 | 4:00 PM | 5/24/05 | 9:45 AM | Unrelated Shutdown | Unrelated Shutdown |
| 2 | F | 6/1/05 | 4:30 PM | 6/4/05 | 10:00 AM | Electric Saw | Blade |
| 2 | F | 6/7/05 | 3:15 PM | 6/8/05 | 4:00 AM | Hydraulic Arm | Motor |
| 2 | F | 6/21/05 | 9:30 AM | 6/21/05 | 11:00 AM | Hydraulic Arm | Arm |
Analysis
Step 1: Using the New Project Wizard in Weibull++ 7, select to create an Event Log Folio, as shown next.
Step 2: On the Other page of the Event Log Folio Control Panel, select the Allow System column option, which allows you to identify the system that experienced each event. Enter the data from Table 1 into the Data Sheet, as shown next.
Step 3: On the Main page of the Control Panel, select M-1 from the System drop-down menu. Enter January 1, 2004 for the Start Date and 8 AM for the Start Time. Enter June 24, 2005 for the End Date and 5 PM for the End Time. Make sure that the System is New on Start Date option is selected so the system will be considered new at the start of the analysis period. The System area on the Main page of the Control Panel will look like the one shown next.
Step 4: Repeat the previous step for the M-2 system using the same data.
Step 5: Set the shift pattern in the Shift Pattern window, as shown next.
Step 6: Calculate the failure and repair distributions for the data set then click to display the results in the Results Panel, as shown next.
