Waterfall Chart+

Overview

When to use it

Use Waterfall Chart+ when you need to:

• Show how losses take a start value down to a result, such as an OEE loss balance.
• Explain an energy, material, cost or production balance from start to end.
• Mark checkpoints in the balance, such as a subtotal after each group of losses.

Choose Combo Chart+ when the values are independent of each other, or when you must follow them over time. A waterfall only makes sense when the bars form one sequence.

Before you begin

• Prepare one numeric PI Point or AF attribute for each bar. Waterfall Chart+ does not calculate: the steps and the totals must exist as values in the PI System, for example as AF analysis outputs.
• Store a loss as a negative number and a gain as a positive number. If a source delivers a loss as a positive number, you can flip it later (see Flip a step that points the wrong way).
• Keep the data sources in the order the bars should appear. The first data source is always the start of the balance and is drawn as a total.
• Use values that share one unit. The chart adds and compares them as they are.

Add and set up the symbol

1. Select Waterfall Chart+ in the PI Vision symbol gallery.
2. Drag the data sources onto the display in the order of the balance: the start value first, then each step, with a subtotal or the end result where you want a checkpoint.
3. Right-click the symbol and select Configure Waterfall Chart.
4. Under Trace Options, select each data source that is a checkpoint and set Total to ON.
5. Close the pane. The symbol shows the start and each checkpoint as a full bar from the baseline, and every other bar as a step that falls or rises from the running total.

Common tasks

Mark the start, subtotals and end as totals

Use this when a bar must show its own value from the baseline instead of a change, for example the value after each group of losses.

1. Right-click the symbol and select Configure Waterfall Chart.
2. Under Trace Options, select the data source in the list (1).
3. Set Total (2) to ON.
4. Repeat for every data source that should be a total.

The bar is drawn from the baseline up to its own value and the running total continues from it. A total does not add up the steps before it: if the data does not agree, the chart shows the gap.

If you leave Total off for a checkpoint, the chart treats its value as one more step. In the next image, Operating Time is a step, so its 84.5 % rises from the running total and the later bars float high above the baseline.

Flip a step that points the wrong way

Use this when a source delivers a loss as a positive number, or a gain as a negative number. The chart draws a negative value as a step down and a positive value as a step up.

1. Under Trace Options, select the data source in the list (1).
2. Make sure Total is OFF. Invert is not available for a total.
3. Set Invert (2) to ON.

The chart multiplies the value by -1, so the bar and its label change direction. In this example the source already reports a loss as a negative number, so Invert turns the -10 % loss into a +10 % gain. Switch it on only when the sign in the data is wrong.

Color increases, decreases and totals

Use this when the default colors clash with your display or your plant standard.

1. Right-click the symbol and select Configure Waterfall Chart.
2. Open Coloring. Make sure Mode is Default.
3. Select the color for Total (1), Positive (2) and Negative (3).

Total bars, increases and decreases take their own color, and the data labels follow the bar color.

To give single bars their own color, set Mode to Custom. Then select each data source under Trace Options and choose its Color.

Label the bars with their values

Use this when readers should see each value without hovering, or when thin steps need a readable label.

1. Open Data Labels. Make sure Show is ON.
2. In Position (1), select where the label sits: Auto, Outside, Inside, Inside Bottom or Inside Top.
3. Set Background (2) to ON to put a badge in the bar color behind each label.
4. Set Units (3) to ON to print the unit after the value, or to OFF to show the bare number.

Every bar shows its value. A step shows its signed change, and a total shows its own value. Inside centers the label in the bar, which keeps the label of a thin step readable.

Name adds the data source name to each label. The name already appears on the axis, and on a narrow vertical chart the labels overlap, so leave Name off unless the chart is wide.

Zoom the value scale on the losses

Use this when the losses are small next to the total and you want to compare them. Total bars start at the lowest value of the scale, so a zoomed chart no longer shows the totals from zero.

1. Open Value Scales.
2. Under Value Scale, set Scale Range (1) to Custom.
3. Enter the lowest value in Minimum (2) and the highest value in Maximum (3).

The scale shows only the chosen range and the steps get taller. Choose Auto to let the chart fit the scale to the values again.

Read the balance from top to bottom

Use this when the category names are long, or the symbol is tall and narrow.

1. Open Common.
2. Under Orientation (1), select Horizontal.
3. Open Value Scales. Under Axis X, set Invert Scale to ON.

The bars run from left to right and the names sit on the left. Without Invert Scale, the first data source is at the bottom. With it, the balance reads from the top down.

Use the symbol

• Read left to right (or top to bottom on a horizontal chart). Each step starts where the previous bar ended.
• Hover a bar to see its tooltip.
• A step with no good value draws as 0.
• Display time: the chart follows the PI Vision display time. In a live display the bars update with new values. To show an average or another statistic over the range, see Value Type in Trace Options.
• The symbol only displays data. It does not write to the PI System or change other symbols.

Configure the symbol

Right-click the symbol and select Configure Waterfall Chart.

Common

Style

Grid

Bars

Coloring

Data Labels

Tooltip

Value Scales

The value scale is always linear.

Trace Options

Numbers

Troubleshooting and limitations

Limitation: Waterfall Chart+ shows the values it receives. It does not calculate differences, sums or percentages.

Limitation: The value scale is linear. A logarithmic scale is not offered.

Limitation: The bars follow the order of the data sources. The chart does not sort them.