By contrast, accounting is the gold standard of business model disciplines.
Accounting is mature, with a long history and hundreds of thousands of profes- sional practitioners around the world, accountants who focus their efforts on cre- ating and interpreting accounting models. Over its history, accountants have developed Generally Accepted Accounting Principles (GAAP), a framework for how to create accounting models for different real-world situations. GAAP is a standard for accounting fidelity, for judging when an accounting model is an accu- rate enough reflection of the company modeled. GAAP is a kind of threshold for fidelity; if a financial statement complies with GAAP, it is high enough fidelity for professional accountants to put their seal of approval on it.
Perhaps each of our four model discipline should have thousands of profes- sionals and its own GAAP. There should be a business process GAAP that governs whether a particular business process model is an accurate enough reflection of a business process as practiced by a specific organization. Such a business process GAAP might include guidance—for example, that an unusual situation that occurs 0.1% of the time need not be modeled, but if the situation occurs 5 percent of the time, it must be modeled.
No such business process GAAP exists. Business process modeling is not mature enough yet. Until then, we must content ourselves with degrees of fidel- ity, without any professional consensus about how much fidelity is enough. Until consensus is achieved we must rely on our own judgments.
All eight require human interpretation. (Direct execution also involves computer interpretation.) And to be interpreted by people, a model must be understandable.
Some model disciplines are inherently difficult to understand. For example, the US Department of Defense uses the IDEF family of languages for both busi- ness modeling and data modeling. Most people find IDEF diagrams difficult to read and understand. IDEF requires much training, not just to create the diagrams but to interpret a diagram created by others. As a result, IDEF is not widely used outside the US military and its contractor community. In contrast, the four model disciplines described in this book have been engineered for easy understanding, so people can read a model created by others with little or no training.
Too Big to Understand
An overly large model is not useful: it cannot be comprehended, and so the pur- pose of the model will not be achieved. ConsiderFigure 2.3, a diagram that shows strategy alternatives for Adelina—one of the Cora Group’s restaurants—and the consequences of the different alternatives. This Adelina strategy example will be explored more thoroughly in Chapter 3, but for now, notice the size and com- plexity of the model. There are 14 model elements inFigure 2.3and 18 associa- tions among these model elements. Parts of the model are understandable on their own, but the whole is too complex to understand all at once.
If a model is too big to be understood, it will be ignored. If you hope to train some people with the model, they will fail to learn what you are teaching. If the model is to be analyzed to transform your business, the analysts will ignore the model and rely on their own judgments and biases. If the model is to serve as requirements for software development or implementation, the resulting systems will not match the business need. An overly large model is a bad model: It cannot be comprehended, and so the purpose of the model will not be achieved.
Large models likeFigure 2.3are common; in fact we have seen many models that are much bigger and more complicated, some with over 100 model elements in a single diagram. Beginning modelers often build models that are too big and too complex; they often ignore the limits of human comprehension.
How big is too big? A useful rule of thumb is that a model should have no more than nine elements. Nine is about how many things a typical person can keep in her head on a good day [Miller, 1956]. Beyond nine, people often get con- fused. And if the model you built confuses the people who read it, the fault is yours, not theirs. Your model is not easy to understand.
Of course the world is more complex than can be shown with nine elements.
Adelina does have three alternative strategies, each with its own consequences.
In fact there are more. There are other consequences of these three not shown inFigure 2.3and other strategy alternatives not depicted. There is always a ten- sion between complexity and comprehension, between the great complexity of the world and the human limits of comprehension. In Chapter 7 we describe three solutions to this problem, three approaches to resolving this tension.
The Appeal of Attractive Models
Model aesthetics matter. Attractive models are easier to understand and more readily accepted than ugly models. Attractive models are therefore more useful.
Consider the business process model shown inFigure 2.4. This is a valid busi- ness process model, and it is simple enough, but it is ugly. The process shows the activities performed by a server, a bartender, and a cook in taking drink and din- ner orders in a restaurant, preparing them, and serving them. Figure 2.5shows the same business process model after a makeover; it has the same modeling ele- ments and flows, but they are arranged in a manner that is visually appealing.
Why care about the attractiveness of a model? The people who read and inter- pret the business process model aren’t going to care if it looks good. They just want to read it to do their job: understand the new process, analyze the old
Double Revenues by Jan 2009: objective
channels efforts toward
channels efforts toward channels
efforts toward
Move to New Location: strategy
evokes evokes
evokes evokes
evokes
Less Romantic Ambiance: influencer
is judgment of
Lose Customers to Less-Pricey Competitors: threat is judgment of
May Lose Disappointed Regulars to Competitors: threat
Lose Indignant Customers: threat
is judgment of
is judgment of Change Decor to Suit
Business Customers: tactic
Restaurant Moves Often Strand Customers: influencer Closing for Events Disappoints
Some Customers: influencer part of
is judgment of
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affects
affects
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Restaurant Move May Lead to Revenue Trough: threat Price-Sensitive Customers
Reevaluate: influencer
Reputation as Overpriced: influencer Market to Business
Events: strategy Raise Prices: tactic
FIGURE 2.3 A motivation model with too many elements
Wrong But Useful 27
one, or check compliance that the work performed in the organization actually matches the activities in the model. So why does model attractiveness matter?
Model attractiveness matters because people will have emotional responses to the model they see. Their emotional responses will affect their ability to under- stand the model and will influence their acceptance of it. In our experience, attractive models are much easier for people to understand and accept than ugly models.2Attractive models are therefore more useful.
2To some extent, attractiveness is culture-dependent. An appealing model in Norway might or might not look good in Japan. But even if the particulars of what makes a model look good vary, the importance of model aesthetics seems to be universal.
BartenderChef
Server
Mix Drinks
cook dinner
Take dinner order Take drink
order
Serve drinks, mention specials, and answer quesitons about the
menu
Serve dinner
Restaurant
FIGURE 2.4 An ugly business process model
Restaurant ChefServerBartender
Cook Dinner Take Drink
Order Serve Drinks Take Dinner Serve Dinner
Order
Mix Drinks
FIGURE 2.5 An attractive business process model
This should not be surprising. Don Norman describes a similar phenomenon with user interfaces of software applications—that people find attractive user interfaces easier to understand [Norman 2004]. Model diagrams are visual. In a sense, the diagrams are the user interface to the mathematics behind the model.
So, just as attractive user interfaces are easier to understand and are more effec- tive, attractive model diagrams are easier to understand and accept.
The unconscious emotional response to an attractive model has another effect: It makes the model more persuasive. As described in Chapter 1, models are not just used for communication. They are also used for persuasion.
You don’t have to be a graphic artist—or hire one—to make a model attrac- tive. Some simple care with the size and placement of model elements, and with consistency in labeling will accomplish most of what you need. Many modelers today pay little attention to aesthetics, so some attention to graphics will make your models much better than most.