Visio is a diagramming package built on the concept of SmartShapes, which are drawing objects that behave in an intelligent way when manipulated.

Once the main product of the independent Visio Corporation, it was absorbed into Microsoft a couple of years ago and is now marketed as part of the Office family. It is a hugely flexible package, offering technical drawing, software modelling, network design, project schedules and floor planning tools.

Visio is programmable, with full support for Visual Basic for Applications, and so can be used as part of custom solutions. You could lay out a seating plan for a theatre in Visio, and link it to a database, so that booked seats were in a different colour from available seats. A more sophisticated solution might let you enter seat bookings directly from Visio.

Although Visio 2000 was the first Microsoft edition, this one has much more of the Office look and feel. It remains an MDI (Multiple Document Interface) application, demonstrating that Microsoft continues to back-pedal on its commitment to standardise on SDI (Single Document Interface).

Documents can have one or more tabbed pages, and you create your drawing by dragging shapes from Visio stencils, each of which displays as a window containing a library of shape masters. Once on the page, you can connect shapes using the connector tool. Each shape has predefined connection points, and Visio connectors snap easily into place. Visio also supports templates, which let you reuse a set of stencils, macros and page settings.

Visio comes supplied with a range of stencils and templates, and these form a large part of its value. The Standard edition comes with shapes for flow, organisation and marketing charts, office layouts, maps and project schedules. The Professional edition adds other templates such as website, network, software and database diagrams, floor and site plans, and process engineering. These templates can pack in a lot of functionality.

For example, the Organisation Chart installs its own menu and toolbar, and the shapes understand hierarchy; so if you move a shape with subordinates, its subordinates move with it. You can also create synchronised copies on different pages of the chart.

There is import and export functionality with Excel, and automatic chart layout. When you are done, you can easily embed a chart into another Office document, typically Word.

The core of Visio's capability is in the SmartShapes themselves. You can understand a shape in detail by displaying a property window called the ShapeSheet, which shows all the specifications of a Shape in a spreadsheet.

The functionality of a Shape is a combination of its geometric appearance together with custom connection points, properties and formulae. A Shape formula can call a VBA function, so there are few limits to what can be done. Shapes support events so, for example, you can have code that fires when a shape is dropped onto a diagram.

Custom properties are also important. In laying out an office plan you might want to include the name of the person who will use a piece of equipment, its price, supplier, and who to call for maintenance. Using Visio custom properties, all this information can be added.

Shapes also have text blocks for captioning individual shapes on a diagram. Text blocks support rich formatting, and you can change their position through a Text Block tool. This is handy when you want to squeeze text into a full diagram. It remains attached to its shape, so the two will still move together.

Many of the new features in Visio 2002 are cosmetic, although still significant. The interface is considerably improved, with faster screen update, better graphics with richer colour support, and a smarter work area with windows that dock, float and resize themselves in a logical manner. You can now also merge windows into a single tabbed window.

New users will like the chunky New Document Type dialog, which uses the Office XP task pane to display the available templates, complete with a descriptive text that appears as you move the mouse over each one.

Microsoft has tweaked and supplemented the Visio stencils and templates. For example, the website mapping template can display site elements in a tree view. SQL Server 2000 is now properly supported for reverse engineering of database schema. You can import data from Microsoft Project to create Visio timelines, and there is a new stencil for 3D directional maps.

When it comes to core functionality, the new features do not amount to much. One interesting area is XML support. Microsoft has developed an XML for Visio file format, which is documented on the MSDN (Microsoft Developer Network) website. This lets you export a drawing as XML without loss of data.

The idea is that third-party applications will be able to parse and generate Visio-compatible files. It sounds good, but the key to useful XML is in standard schemas that enable rich data transfer between applications.

Visio XML, on the other hand, is geared towards storing its own proprietary format. It still has some value, but less than it would if Microsoft were to sit down with the vendors of related modelling and drawing tools to thrash out an agreed XML schema that would provide interoperability. In practice, users will continue to use de facto standards like the Autocad file formats to port drawings, albeit with loss of data.

The way Visio is marketed has changed for this new version, and not everyone will be happy with the results. In the old scheme, there were two intermediate versions of Visio, one for engineering and one for IT, and an Enterprise edition that offered high-end features like Network discovery, where Visio automatically creates a diagram of your network through SNMP (Simple Network Management Protocol).

The new Visio has only one Professional edition, which combines the features of engineering and IT, and its Enterprise version has disappeared. Network professionals are now offered a downloadable add-on called Enterprise Network Tools, which provides the auto-discovery tools and additional stencils. It is subscription based, which has some advantages since network hardware is constantly changing.

The most controversial area is Visio's UML and database diagramming features. In the old Visio, this provided code generation from UML diagrams, automatic UML integrity checking, reverse engineering of software projects, the ability to generate DDL (Database Definition Language) code from database diagrams, and a rich choice of modelling methodologies. Users were looking forward to improvements in this version, particularly in UML reporting.

The bad news is that Visio Professional has much of this functionality stripped out. You cannot even generate DDL from a database diagram, which means that having designed your database structure, you have to manually recreate it in the database of your choice. Code generation from software diagrams has also gone. Put another way, these features in Visio Professional are only useful for analysis, rather than as part of the development process.

The advanced features will be reappearing in some guise or other, as part of Visual Studio.Net. The old Visual Studio Modeller, which was a cut-down Rational tool, is being replaced by a Visio version. It is understandable that Microsoft is making this change, but the worry is that Visio's value as a general purpose diagramming tool for software professionals will be undermined by its role as an add-on for Visual Studio.

The initial signs are not promising. An obvious requirement for a software-modelling tool is the ability to generate Java code. The Java shapes have not been enhanced at all in Visio 2002, and the suspicion is that, since Microsoft is not a Java advocate, this functionality will not be part of the developer's version of Visio when it finally appears.

The core Visio product, though, is superb, and in this version better than ever. It's ideal for those looking for a general-purpose diagramming tool at a reasonable price.

PRICES: Standard £180.95 (£154 ex VAT); Professional £414.78 (£353 ex VAT); Enterprise Network Tools £470 (£400 ex VAT).

CONTACT: Microsoft
0345 002 000
www.microsoft.com/office/visio