Push Volatile Data Into the Background

Some data is so volatile from period to period that there's less meaning in the fluctuations then there is in the long-term trend.  Moving averages clearly show the long-term trend, but they move so slowly each period that they don't provide the talking-points your manager desperately wants.  Let me show you how to show a long-term trend, while keeping the volatile, talking-point data on the page, without causing visual noise.  Push volatile data into the background.

This chart shows the six-month moving average production rates of two plants:

This chart is clean and simple, but says a lot:

• Thick moving average lines. The solid, slow-moving lines are clearly the six-month moving averages for Alpha Plant and Bravo Plant, as stated in the chart heading.
• No Horizontal Axis Explanation Needed.  The data is monthly.  The horizontal axis labeling makes this clear, so it doesn't need to be explicitly stated in the heading, or even with an axis label.
• Simple Vertical Axis Label. The units of production rate are described with an axis label.  This is explicit to avoid confusion, but subtle, because your audience usually knows what you're measuring.
• Volatile Data in Background. In the same colour, behind each moving-average line, is the volatile, monthly data.  I've done a few things to de-emphasise these series:
• Moved behind. Each monthly data line is literally behind the moving average line.
• Thinner line. Fat lines are great for moving averages because they emphasise the imprecise, slow-moving nature of the data.  Conversely, very thin lines look precise, but also less important. 
• Hollow data points.  Using data points emphases the discrete nature of the data - each value stands alone.  I think white-filled round markers are great for this.
• Dashed lines.  The dashed line helps to de-emphases the volatile series.  It also helps to guide the semi-random walk from one data point to the next.  You could remove the line entirely, except I find the dashed line is helpful for the eye to follow along from point to point, and it "joins" the data to its moving average.

How to?  Read on if you need some step-by-step help to achieve these results.

• Move data series behind another.  This is done by changing the order of the series in the "Select Data Source" dialog box in the DESIGN tab of the CHART TOOLS tab group.
• Make data series lines thinner, and dashed. This is done by:
• Selecting the series, and then "Format Selection" in the FORMAT tab of the CHART TOOLS tab group.
• Select the "Fill and Line" tab
• Select and expand the LINE section.
• Adjust the Width option to set the number of points of line width that looks right.
• Select the "Dash type" drop-down to select different dashed line options.
• Create hollow data points.  This is done by:
• Selecting the series, and then "Format Selection" in the FORMAT tab of the CHART TOOLS tab group.
• Select the "Fill and Line" tab
• Select and expand the MARKER section.
• Expand the MARKER OPTIONS section.
• Select the "Built-in" radio button, and choose the Type and Size of the marker you want.
• Expand the FILL section below.
• Select the "Solid fill" radio button, then pick the white colour.
• Expand the BORDER section below.
• Select the "Solid line" radio button, then select the colour for the data series.