What does the
"System is new on start date" option mean in the Weibull++ event log?
The event log folio in
Weibull++
allows you to enter information about the dates/times
when a failure (or another type of event) brought a
system down, and the dates/times when it was restored to
operation. The software then automatically extracts the
data sets you can use to analyze the times-to-failure
and times-to-repair.

If you select the System is new on start date
check box on the Main page of the control panel, this
indicates that the system had not accumulated any
operating time prior to the date when you started
recording data in the log. Therefore, the time to the
first occurrence of an event will be recorded as
complete data (State = F in a standard folio data
sheet).
If you clear the check box, this indicates that the
system had already been operating for some unspecified
period of time before you started recording data in the
log. Therefore, the first time will be recorded as
censored data (State = S in a standard folio data
sheet).
When you calculate an event log folio, the software
automatically analyzes the extracted data and provides
the results in two reports that can be accessed from the
Results area of the control panel. To
see the actual data sets that were used to calculate
these results (or if you want to perform other analyses
on your own), choose one of the commands under
Event Log > Transfer Life Data or click one of
the transfer icons on the control panel. You have the
option to transfer the data to a new Weibull++ standard
folio or to replace the data in an existing standard
folio.
Can I use different time units for different types of inputs/results
in Synthesis applications?
With the release of Version 8, all of the Synthesis
Elements (Weibull++,
ALTA,
BlockSim,
Xfmea
and RCM++)
allow you to specify different time units for data,
inputs and results.
To manage the time units available within any given
Synthesis repository, an authorized user can choose
File > Manage Repository > Manage Units.
For example, using the default equivalencies shown in
the following picture, 1 day = 24 hours, 1 month = 730
hours, and so on.

While performing analyses in this repository, users
will be prompted to specify the time units when
applicable, and they can change the units later if
necessary. For example, in a Weibull++
standard folio:
- You can select the units in the
setup window that appears when you create a new data
sheet.
- You can change the units for an existing data sheet
by clicking the Change Units icon on the control panel.
You will have the option to leave the existing numbers
unchanged (e.g., 10 days becomes 10 hours), or to
automatically convert the data using the specified base
unit equivalency (e.g., 10 days becomes 240 hours).

- When you calculate results in the QCP, you can use
the Units drop-down list to choose the units that will
be used for the time inputs and/or results.

Likewise, when defining the universal reliability
definition (URD) resources that can be maintained from
any Synthesis application, it may be more convenient for
users to make some inputs in terms of months (e.g., the
scheduled interval for preventive maintenance), other
inputs in terms of days (e.g., the logistic delay while
waiting for a repair crew to be available) and still
other inputs in terms of hours (e.g., the time required
to perform the repair).

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