As with ignitions, the distribution of population varies according to the time of day, and the examples file has separate folders of population for day and night, and different selections of populations for the Day and Night Run Rows, with the Night populations shown as greyed out because the active Run Row is a Day row.

Vulnerabilities

The Vulnerability data specify the criteria for causing fatalities or other types of damage from different types of hazardous effect. The program is supplied with two sets of data for personnel vulnerabilities, one for people out of doors, and one for people indoors.

Risk transects

A risk transect is a line drawn on the map. You use it to view a Risk Transect Graph that shows the levels of risk along the line. You can define any number of risk transects.

Risk transects are not available in Safeti Lite.

Risk ranking points

A Risk Ranking Point is a location drawn on the map, as a location of interest for detailed riskcontribution results. You can define any number of risk transects.

Risk ranking points are not available in Safeti Lite.

Plant Boundaries

You can draw the boundary of the plant as a polygon on the GIS View, and also use the Data source option in the Data tab of the Ribbon bar to import boundary shapes from an external GIS database. The risk calculations uses the boundary to distinguish between onsite and offsite sources of ignition.

The Boundaries folder is shown as greyed out. It would be shown as selected if it contained a Boundary that was selected for the active Run Row.

Plant boundaries are not available in Safeti Lite.

Viewing input data

The section above introduced the main types of input data and their organisation. This section describes how to work on the details of the input data.

The input dialog for the Propane Pressure Vessel Equipment item

In the Models tab section of the Study Tree, expand the Propane Storage Study, and then double-click on the icon for the Pressure Vessel Equipment item named Propane. The Pressure Vessel Equipment input dialog will open as shown on the next page.

The dialog contains a large number of input fields organised over nearly fifteen tab sections, but you will not normally enter data in

every section. For an Equipment item, the most important inputs are in the Material tab section, which covers the process material and operating conditions. Almost all of the fields in the other tab sections are also present in the Scenario dialogs, and you would set a value in the Equipment dialog if you want the value to be used as the default value for all of the Scenarios under that Equipment item.

Describing every item of input data is beyond the scope of this tutorial. However, you can get a description from the online Help that is included with the program.

Every input dialog contains a Help button at the bottom right. When you click on this button, the Help will appear in a separate window, as shown.

The Help Window will be displaying a description of the current tab section, but you can use the links inside the topic and the Contents, Index and Search tabs to reach any topic in the Help system and gain a full understanding of the way that the input data will be used in the calculations and the appropriate values that you should set for the hazardous events that you want to model.

After you have finished exploring the Propane Pressure Vessel input dialog, click on Cancel to close the input dialog without saving any changes you might have made. If you wish, you can move to the other tab sections in the Study Tree and explore the input dialogs for other types of data.

The Grid View allows you to work on input data for multiple items

The input dialogs allow you to work on the input data for a single item at a time, and the Help button and the organisation of the tab sections mean that the dialogs are the best way to work on data when you are still becoming familiar with the details of the input data.

However, once you have become familiar with the data, you may find the Grid View useful, as a method of working with input data that allows you to view and edit the data for more than one item at a time. The Grid View appears in a separate tab section in the Document View area, i.e. in the same area as the GIS Input view.

To view the data for both of the Pressure Vessel Equipment items, take the following steps:

1.Select the workspace node at the top of the tree.

2.In the Grid View, bring up the list and select Pressure vessel from the list as shown.

This list is known as the “filter list”, and it allows you to choose the type of item whose data you want to view in the area below the toolbar.

Once you have made the selection from the list, the data for the two

Pressure Vessels under the folder will be displayed in the Grid View as shown, with the data fields displayed as a wide list of columns, as in a spreadsheet.

If you select one of the Studies from the tree, the Grid View will display only the Pressure Vessel in that Study, and if you change the selection in the filter list to Leak, the Grid View will display all of the Leak Scenarios under the selected node.

This can be very useful for obtaining an overview of the input data, and for comparing values between different items. The Grid View can also be a convenient way of setting up input data, as you can copy and paste values between cells in the Grid View, and also between a spreadsheet and the Grid View.

This tutorial does not give further details on using the Grid View, and you should refer to the online Help for a full description.