IENG 423 Design of Decision Support Systems Modeling with Excel Excel Basics Charts and Graphs to Communicate in Decision Support Systems

Using Charts and Graphs Excel is pretty good as calculating and recalculating sets of data, sometimes very large sets of data In some situations it may be difficult to tease out the findings, estimates, or best courses of action from a lot of numbers Charts and graphs can help to communication the DSS’s message

Charts and Graphs In most cases charts and graphs show (visually) relationships Investments and Return on Investments No. of assembly stations and output volume Component suppliers and product quality

Charts and Graphs In simplistic terms creating a chart/graph involves Selecting the columns or rows that represent the relationship that you want represented graphically  This implies that there are multiple rows/columns Then, click on the Chart Wizard on the tool bar That’s it… sort of

Charts and Graphs Pick your charts type Then pick your chart subtype, if any You can see a sample, if you want Next… Confirm or select the data range for the chart, and let Excel know if the data is organized by row or column Select the series tab to make adjustments to the data series for the chart…  What is a series?

Charts and Graphs Next… Enter chart title Enter X and Y axis labels if appropriate Tell Excel where you want to put the new chart  New worksheet  Existing worksheet, if so which one

Charts and Graphs Click FINISH And that’s it, if you want it to be

Charts and Graphs Some things to remember Chart Options - If you right click on the chart, and click on Chart Options from the popup menu, you change about any property of your chart Chart Toolbar - When you select a chart by clicking on it, you will see a Chart Toolbar Select an element – if you right click on an element of a chart you will have the option to change the properties of that element

Charts and Graphs Some properties you can change… Titles (chart, axes) Axes Gridlines Legends Data labels Data table Chart background Line or data properties (colors, line, markers)

Charts and Graphs But, the results may not be exactly what you wanted Remember your DSS is for a client/customer/boss Presentation is important Don’t ever assume that the DSS user will understand a few bars on a grid But, not to worry, you can dress it up

Charts and Graphs Things you might want to add or fix Chart Title X and Y axis labels Legends Line or data colors Grid lines …

Charts and Graphs Some properties you can change… Titles (chart, axes) Axes Gridlines Legends Data labels Data table Chart background Line or data properties (colors, line, markers)

Charts and Graphs So let’s do an exercise You have factories in five states You have widget production output data as well as production capacity data

Charts and Graphs So let’s do an exercise Create a validation list on sheet2 for the state codes, Then on sheet one enter the following table using data validation for the state code StateOutputCapacity WV58 VA47 MD711 PA912 NY914

Charts and Graphs So let’s do an exercise Create a vertical bar graph of state for output Add a second series – capacity

Charts and Graphs Trendlines In some cases you may want your DSS to project beyond the actual data that you have… That is you want it to do statistical or mathematical projections Excel has a convenient tool to add trendlines to a chart…

Charts and Graphs Trendlines You can only add a trendline to some data, if it makes sense to do so (dah!) Data must be of the proper type  Nominal numbers – no What’s next?  Quantative numbers Ordinal Ratio

Charts and Graphs Trendlines After you have created a chart (probably a line or bar chart)… Select the line that you want projected  i.e. sales volume by month, for example Right click and click “Add Trendline” from the popup menu You will see a trendline dialog box

Charts and Graphs Trendlines Pick the type  Linear, Logarithmic, Polynomial, Power, Exponential, Moving Average Depending on the type you select you may have to set a parameter Select Options  Most important – By how many units of the X variable do you want to project the data You can change the properties of the trendline after it is created

Charts and Graphs Trendlines Pick the type  Linear, Logarithmic, Polynomial, Power, Exponential, Moving Average Depending on the type you select you may have to set a parameter Select Options  Most important – By how many units of the X variable do you want to project the data You can change the properties of the trendline after it is created

Charts and Graphs Trendlines – another exercise You have widget sales data for all factories for the first eight months of the year You need to project the widget demand for the remainder of the year

Charts and Graphs Trendlines – another exercise Make a validation list on sheet2 containing a three letter abbreviation for each month (Jan, Feb,…) Use this list to create a pulldown list and validation for entering the data table on the next slide

Charts and Graphs Trendlines – another exercise Widget Demand data from first eight months of year MonthDemand Jan20 Feb15 Mar19 Apr29 May35 Jun36 Jul40 Aug45

Charts and Graphs Trendlines – another exercise Create a line graph showing the demand data over the eight months of available data Add a Trendline showing a linear projection of this data for the remainder of the year (Sep…Dec)

Diagrams Diagrams are not particularly part of a DSS … but can be useful in explaining concepts, setting context, etc. Excel has some useful tools for creating diagrams

Diagrams Excel diagram types Org chart Cycle diagram Radial diagram Pyramid diagram Venn diagram Target diagram