The term "Historical Data" will fall under the purview of several areas of PlanetTogether. Regardless of the area referencing Historical Data, all historical data can be leveraged primarily to track performance and conformity to the schedule. The areas where Historical Data come into play are listed below:
Using Historical Data
Historical Data can be used for performance tracking of the resources within a scenario and to track the conformance to schedule.
By accessing the Activity Status of an operation, a user can record the reported hours (setup, run, post-processing) and recorded quantities (good and scrap). PlanetTogether can then compare the actuals with the expected hours and quantities to provide a performance report. The scope of the performance report is limited to the aggregated expected hours and quantities that are set to run on that resource.
A performance of 100% means that the reported quantities and hours match the expected quantities and hours completely.
Scenario Histories are stored to the disk from PlanetTogether in files about 500 bytes large. Each Scenario History tracks the changes made to the schedule in that particular historical snapshot. Scenario Histories can be accessed by selecting the "Scenario History" tab of the Views drop-down menu. It will include the following data:
- Description: This will identify the nature of the change, for example, "Changed NeedDateTime from '1/4/2012 12:00:00AM' to '2/29/2012 5:00:00AM.'
- HistoryType: This is the action that has caused the change, for example, "JobChanged."
- Key: This is a unique identifier for the object affected by the action.
- ObjectType: This is the type of object that has been affected by the action (i.e., "Job").
- TimeStamp: This is the date and time the change occurred.
- User: The user that made the change.
Maximum Number of Histories Stored
This is a part of the System Options dialog that determines how many histories are preserved. Having a large maximum allows for more accurate performance reporting and could help stabilize standard lead times and improve future projections, but will also take more disk space as each history stored is stored in a file about 500bytes in size. These histories will also have an impact on the load times and overall performance of PlanetTogether.
Another way to track the performance and conformity to the schedule is to Track Actuals. In PlanetTogether, Actuals represent a finished activity that has reported Start and End dates. This feature is enabled in the Tracking Data tab of the System Options by setting a value for the "Track Actuals Maximum Age" field. When enabled, finished activities will have their reported Start and End dates set, and they will appear on the Gantt for the duration specified. They will show up either at the current clock or in the past (within the gray area before the current clock time). It is also possible that finished activities appear in the future if their reported Start and End dates are set later than the current clock date/time.
Whenever the Scenario is published, the internal PlanetTogether data set is copied, typically into SQL Server. PlanetTogether can be set to store multiple Published Scenarios on the SQL Server database. As with the Scenario History, any number of Published Histories can be recorded, providing larger sample sizes when determining the performance of Resources or how closely the Resources are conforming to the expected schedule.
Keeping Publish Histories has also been of great benefit for manufacturers who are unsure of their standard lead times, as is the case for many manufacturers who have grown rapidly in a short period of time. In addition, by keeping a large enough sample size of Published Histories, more accurate time standards can be derived by averaging the Actuals.
Recordings are different from the aforementioned Histories in that they do are not typically used for tracking Performance or Conformance to Schedule. Instead, recordings are PlanetTogether-generated copies of the data set found within PlanetTogether. Within each Recording is several stored transmissions. Recorded transmissions can be any change or movement within PlanetTogether, from accessing a dialog window to triggering the Refresh of the planning data. Recordings are therefore helpful as backup scenarios when PlanetTogether crashes. Each logged transmission is separate from the others to help pinpoint and locate potential bugs or errors in PlanetTogether. The Recording file can be used to restore the data set should the scenario become corrupt or lost.