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VisioModeler
 
 
 


29 Jan 2000

by Duncan Dwelle

 

 

InfoModelers acquired by Visio!

 
  Well, that's no longer news; it's history. And so far, a step backward. When Visio first acquired the product InfoModeler and the company InfoModelers, they rolled the former into Visio V5 as VisioModeler. 

The good news is that Visio 2000 Enterprise edition has now dropped the separate ORM product and integrated it into Visio. The bad news is that so far it is a very limited and weak implementation. We were better off with VisioModeler, even considering how broken it was. And it was so broken that we, who love the idea, abandoned it for the fourth and final time in 1999. We built our own ORM tool, using Visio, before Visio did.

Since I am tremendously unimpressed with the ORM modeling included in Visio 2000, I've only slightly modified the review of VisioModeler below to give you a flavor of what once was and may again be.

 

 

 

 

Scope

 
  VisioModeler aspires to be "a database design tool that allows you to manage every aspect of database design - from communicating with clients to producing a physical schema." This now includes reverse engineering as well as forward design.

As you will see in my conclusion, I feel these ambitions are not yet fully realized in the product. Nonetheless VisioModeler asks to be judged in the context of the complete database design lifecycle and it is a credible contender in all aspects.

VisioModeler presents three distinct, separate, yet integrated perspectives on database design. The conceptual model is expressed in Object Role Modeling or ORM, a formal and powerful modeling language for expressing information structures. From a valid conceptual model you can immediately generate an automatically normalized logical model of tables and columns, selectable between IDEF1X or relational notation. Finally, from the logical model you can generate a physical schema or database specification, either as a DDL script set or as direct DBMS catalog updates via ODBC.

 

Context

 
  VisioModeler is distinctive, in fact unique for practical purposes, in offering a truly conceptual model of information structures.

N.B. I believe that there is no such thing as a conceptual entity-relationship model because entities are inherently not conceptual. They are a mathematicians' abstraction of a collection of value holders - not your typical business user's concept of how things work. I'll be writing more about this position shortly and I'd be pleased to argue it with you in e-mail.

There are a handful of other products based on ORM or its progenitor, NIAM. But none of these is a commercial reality today outside of Australia and perhaps the Netherlands. There are a few additional products, such as Silverrun's ERX, which are based on Chen or Merise methods and therefore claim to be more conceptual than IE or IDEF1X. Whether they are is debatable; I say they are not. Thus I classify VisioModeler as the only truly conceptual data modeling tool readily available.

 

Structure

 
  A model in VisioModeler is composed of one or more model documents (*.IMO) and an associated data dictionary file (*.IMD) per model. Thus models are quite modular and portable. The Enterprise edition of VisioModeler allows multiple model documents to be managed and integrated as a project, thus supporting multi-user partitioning of work in different subject areas.

Installation flows smoothly through a standard InstallShield wizard and places a modest footprint on your system. I've run VisioModeler V3.0 on both a 486 laptop under Win95 and a Pentium Pro under NT 4.0. Both were well behaved and polite to their respective environments.

 

Foundation

 
  As noted above, it is it's Object Role Modeling foundation which makes VisioModeler so special. This is more than the graphics of the conceptual model; more than the conceptual model itself. It is certainly manifested in the visible ORM notation of VisioModeler's conceptual model - those distinctive ovals and rectangles.

But ORM is not just the symbols. ORM is a complex and complete language for expressing data structures. Whether a model is created with ORM notation in the conceptual model, drawn as an IDEF1X entity relationship logical diagram, or reversed from an existing database, VisioModeler's internal understanding of the model is expressed in ORM. That means the various visible forms are logically equivalent even though notationally different. By extension, a change in one form (e.g., conceptual or logical) is directly applied to the other forms.

While the pervasive ORM foundation is a virtuoso display of coding skill, it is only a fraction of VisioModeler's impressive demonstration of top notch technology. Dockable tool bars and all the fancy GUI widgets, OLE hosting, ODBC and direct database drivers, intelligent (if not perfect) SQL creation for complex constraints - the evidence of technical mastery is unimpeachable. InfoModelers (the company) had some world class talent building this product.

 

Interface

 
  Unfortunately, the brilliant scientists who've harnessed ORM into VisioModeler have apparently been locked too long in a dark room with nothing to read but standards manuals. There is too much sensory overload and too little common sense in the user interface of VisioModeler for me to love it. More than a few of my knowledgeable associated have commented that they couldn't make head nor tail of the product in the typical half hour allotted for casual evaluation.

Menus aren't bad; let's give them that much. There are no excessive levels of nested menus and hidden items at the bottom of long paths. Tool bars are another story. I work on dual 21" monitors side by side so screen space is not generally a problem. But VisioModeler puts my real estate management to the test.

Page grids, pagination controls, alignment icons, drop-downs, pop-ups, pull-overs ("Pull over, mister. I'm booking you for GUI."), tabs, spinners ... The File / Preferences dialog has seven tabs (stacked 4 + 3) One of those has a drop-down list to morph into three different panels; another has eight variants. And then there are more under Document Options!

Zooming controls are notably clumsy for a tool which consumes prodigious amounts of graphic work space. The only zoom tool icon zooms in the same fixed steps as the View / Zoom menu commands, which take three clicks to fire.

On the good side, dialogs remember the last dialog position, unlike ERwin 3.0 where every dialog opens in the middle of your desk top (mine is 21" x 2 wide) no matter where you closed the last. In fact, where ever it's a question of technology, you can count on VisioModeler, but when it comes to practical judgement my confidence is reduced.

In a land of IDEs to manage your SDLC, I suppose we are expected to become accustomed to Baroque interfaces. But I will not surrender without a fight. I still believe that, all else being equal, simpler is better. Apparent simplicity was the driving force behind PowerDesigner's acceleration from obscurity to market leadership in three years. Yet VisioModeler is a study in visual complexity. If I'm wrong, let me know.

 
             

Conceptual modeling

 
             

Logical modeling

 
             

Physical schema

 

Quality

 
  I personally have found very few show-stopping bugs in VisioModeler and caused only one crash. That one is repeatable but probably fixed by the time you read this (don't try using Ctrl+C / Ctrl+V in the Fact Editor). On the whole the level of code quality seems much higher than the norm, much higher than PowerDesigner or ERwin.

There are, of course a lot of things, from fundamental to trivial, which I would love to see changed or enhanced in VisioModeler. But I do not cast myself in the role of omnipotent judge. The code team are very smart and you, collectively, are even smarter. So my preferences carry only one vote (or perhaps none with the product designers).

 

Conclusion

 
  I'm an ORM bigot, a true believer, and a certified consultant in the method. I really wanted to adopt VisioModeler as my prime tool for at least conceptual visualization and definition of information systems. But I can't.

The obstacles are no longer speed or program stability, as they were in prior versions. What remain are fundamental failures of the mission of modeling:

  • The residual need, after building a satisfying ORM model in VisioModeler, to do it again elsewhere in order to capture dynamic business rules and resulting object methods
  • Imperfect conceptualization in the ORM model - too many physical issues creep in
  • Grossly broken projection of the ORM model into the logical schema
  • Absence of explicit denormalization controls in the logical model
  • Absence of application partitioning - every modeled constraint is generated as back-end database code
  • Missing physical schema features and controls

I used to use VisioModeler frequently and eagerly to investigate thorny problems which didn't yield easily to other means. But I never used VisioModeler to design and build databases. 

Being true believers, we've built our own ORM tool.

 

 

Ask the Experts in Object Role Modeling

 
  Dr. Terry Halpin's articles and definitive text on Object Role Modeling are now available at ORM.net.

Information Conceptual Modeling, Inc. offers about fifty years combined expertise in ORM and NIAM through its principle consultants. And they claim to have the "best wallpaper on the web". If you want to know ORM, you need to know these guys:

Dr. Sharad H, Gadre of IMMS, Inc. has been involved since ORM started and has used VisioModeler since its first release on some of the largest projects to which ORM has been applied.

Bill MacLean is very active teaching ORM to corporate clients and many of running VisioModelers' own classes on the product.

John Miller, while newer to the ORM expert family, is one of our most vigorous thinkers and pratictioners.

Duncan Dwelle here at AIS is also a certified ORM consultant. Check out an ORM fantasy: It's Only a Matter of Time

All of these experts and more are active members of our infomodeler-users@aisintl.com e-mail discussion group (see above).

 

 

Contact

 

 

Visio
(having acquired InfoModelers, 
formerly ConQuer Data, 
formerly Model Data, 
spun off from Asymetrix)

 

 

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