STEM newsletter

STEM 7.2 release

23 October 2009

The latest STEM version 7.2 was released to licensed users on 14 October 2009, with a number of new features designed to make the software more intuitive to learn and easier to use day-to-day by targeting known barriers to acceptance. Current licensees with an active website subscription can download the new version directly.

Please note that, for compatibility reasons, we will not change your soft-licence credentials until you signal your intention to start working with the new version. (If you have been using STEM 7.1 then you will need to load and install STEM 7.1d to keep working with both versions in parallel.) Prospective customers and existing users of older versions of STEM should contact Implied Logic to arrange access to the new version.

The formal launch at the STEM User Group Meeting at the end of September in Cambridge, UK followed a period of beta testing in which a number of unexpected issues were resolved or refined. The feature set was finalised for the User Group event, and a few issues raised by delegates have been addressed prior to final release.

STEM 7.2 overview

A re-designed Click and click again toolbar allows newly created model elements to be positioned directly by moving the cursor and then clicking again.

A new Connection tool provides a more intuitive and visual method of linking elements (rather than the obscure Ctrl-drag-and-drop method), coupled with a simpler interface for connecting Transformation inputs.

A new Text Box tool allows you to add headings and explanatory notes alongside the icons in a view (‘free text in views’), making the principles of a model more evident to colleagues and clients.

A new Results export wizard enables you to link STEM results data into Excel charts with just a few clicks, creating an Excel workbook from the data in selected charts or results views in STEM.

A new Auto-column format option (for new charts of aggregate results such as traffic volume, revenue, capex and opex) overrides the standard line format with overlapping columns (for multiple scenarios, results or elements) or stacked columns (for one result over multiple elements).

This STEM 7.2 release is fully compatible with models created in version 7.1, but models saved with STEM 7.2 cannot be read by STEM 7.1 or earlier versions.

‘Click and click again’ toolbar

The original STEM toolbar would automatically position the icon for a new element at the bottom left of the screen – you then had to drag it into position. In contrast, the toolbar in STEM 7.2 now has a more intuitive ‘click and click again’ operation.

New icons will ‘snap-to-grid’ unless you press <Alt>, and this also now applies when elements are copied with drag-and-drop or pasted.

Method Location of new icon
Click the toolbar, and then click again Mouse cursor (subject to snap-to-grid)
Select Create from the element menu, and then click again Mouse cursor (subject to snap-to-grid)
Click the toolbar while pressing the <Shift> key First available slot (along and up) from the bottom left
Press <Ctrl+Shift+S> to create a new Service (and so on) Ditto: useful if you want to create several elements at once
And implicitly when you create a new scenario Dimension First available slot large enough for the Dimension and Variants

Four ways to create an element

New tool for connecting elements

A new Connection tool provides a more intuitive and visual way to connect two elements than the original technique which used drag-and-drop with the <Ctrl> key. The mouse cursor reflects the wand image from the new tool, and you simply click the two intended elements in turn in order to connect them.

As you move the cursor over potential target elements, the icons are highlighted to ease accurate selection.

Note: the old technique still works, and with the benefit of target highlighting; but it is non-intuitive for new users. Experienced users will be pleased to note that there is no longer a ‘hole’ between an icon and its caption, and this reduces the risk of accidentally creating a copy of an element when using the Ctrl-drag-and-drop method.

You can also select Connect from the element menu to activate the connection cursor, or just press <Ctrl+Q>. The latter method avoids excessive mouse movement, just like the original drag-and-drop technique.

A ‘Link from Selected element’ option causes the tool to connect automatically from the currently selected icon if you prefer to select the icon first and then connect.

Connecting two or more Transformation inputs

In previous versions of STEM, a Transformation element had to be explicitly changed to the Expression type before it could accept multiple inputs. STEM 7.2 provides a new interface for dragging additional inputs which makes this change implicit and automates selection of the next free input slot.

If you connect one input to a Transformation, you will get a simple Multiplier Transformation as usual; but now when you connect another input, a new ‘add’ handle appears at the bottom left of the Transformation icon. Connecting to the add handle results in an additional input, and the Transformation becomes an Expression Transformation (if not already).

Note: STEM prompts if you have already entered some data for the multiplier input of a Multiplier Transformation which would be discarded by the implicit change of type to Expression.

Connecting instead to the icon background pops up the input-selection dialog as before, so you can ‘re-wire’ one of the existing inputs, or choose another free one. The current inputs are now clearly labelled in the dialog. However, the dialog is not shown if you drag onto the background of a Multiplier Transformation: its single input is simply replaced and it remains a Multiplier.

Note: for simplicity, it is no longer necessary to hold down <Shift> to connect one Transformation to another.

Free text in views

If you are a STEM user, then the icon names and automatic links make a model almost self-documenting; but what if you are not familiar with the system? STEM 7.2 has a new Text Box button on the toolbar which allows you to add titles, group headings or explanatory notes to a view, making it clearer at a high level how the key parts of a model fit together.

STEM’s existing notes are analogous to cell-wise comments in Excel, whereas text boxes are much more immediate and are not buried in the model data, more like a ‘Post-It’ (or a comment in PowerPoint).

The creation process is designed to match expectations from using Office applications. So you just click the Text Box tool once, click and drag to outline the intended rectangle, and then enter suitable text as desired. The height of the new text box matches the number of lines of text entered, regardless of the initial ‘rubber-band’ area.

You can modify the font, alignment, border and background of text boxes. The relevant dialogs are accessed by right-clicking the text box border to select from a context menu. When changing any of these settings, you can optionally: apply a format to all other text boxes in the same view, and/or set this format as the default for any newly created text boxes in the same view.

Note: formatting (e.g., bold) is applied to the whole text, not individual words or characters.

Text box formatting dialogs

Results export wizard for Excel

STEM 7.1 provided the facility to export selected STEM model input data to a companion Excel workbook. STEM 7.2 now builds on this with the export of STEM results data from selected charts or results views. In both cases the data can be linked dynamically: inputs defined in Excel link through to the model, and results shown in Excel are updated after a model run.

Model inputs and results linked between Excel and STEM

The usual Results program graph-selection interface is the ‘wizard’ for pre-selecting the data to send to Excel. You first draw graphs of the data you wish to export, or open a pre-defined view of suitable results; and then select Export Results to Excel from the File menu.

STEM exports the data to a new sheet (or sheets) of a workbook in the same folder as the model, and displays the workbook when complete.

Specimen export output (views)

Auto-column format option

STEM graphs have always had a line format by default for maximum readability with respect to potential combinations of multiple scenarios, elements and results. However, while a line format suits instantaneous results such as penetration or installed capacity, a column format is generally preferable for discrete, aggregate quantities such as traffic volume, revenue, capex and opex.

STEM 7.2 adds an option to auto-select a column format for new charts of such aggregate results, using overlapping columns for multiple scenarios, or models, or elements, up to a limit of four series, or stacked columns for one result over multiple elements. (One doesn’t generally expect to sum over separate scenarios, or models.)

Instantaneous and aggregate values

Miscellaneous additions

Myriad changes and minor improvements have been made along the development path since STEM 7.1 was released in 2007. A few of the more significant details are noted below.

  • A new ‘Average connections’ basis is available for Service Requirements and Service inputs to Transformations
  • A top-level ‘note’ can be added to an element directly from the icon menu – previously this item was greyed out until a note was actually defined
  • Parameter validation errors are now highlighted in the status bar
  • The Windows context menu key now activates icon menus
  • Menus show <Ctrl+C> rather than <Ctrl+Insert> – both key combinations are supported
  • New pre-defined results are generated for the net present value of Resource costs, and also for the number of any early-decommissioned units
  • The Choose element to Draw dialog uses more of the screen if there are very many elements
  • STEM 7.2 has a brand-new and conventional wizard-driven installer which should be more readily accepted by IT staff

The single, overriding objective for STEM 7.2 was to make the software easier to learn. STEM has evolved a very rich set of functionality, but historically ease of use has mostly been a secondary design consideration behind functional output. ‘Road blocks’ for new users have been explained via training and support, but not actually addressed.

By adding new features and targeting known barriers, we have made STEM 7.2 easier to learn, and then to use, to hand over, and to package with Excel.   

STEM 7.2d installer

Registered licensees with a current maintenance contract can download the appropriate C-STEM or D-STEM 7.2d installer.

Download now: C-STEM 7.2D-STEM 7.2

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