All models are wrong, some are useful (Edward Deming)

You’ve probably seen many MIS cartographies. You know, those squares and rectangles imbricated, linked each other .. These diagrams contain a lot of information. They are most often maintained by dedicated teams and stored in a database, so that users can zoom in zones, areas, or districts. Users can find an application, its dependencies (but often, the map is not the territory ..) but who are those users? What benefit do they get from that?

As we all know «all models are wrong, some are useful». So what do we need a cartography for? We want to understand and discuss and take collective decisions. «We» stands for executive, managers and operationals.

Today executives don’t understand why we should reinvest in this «project» (note the typical misunderstanding between project and product; they tend to think that when the project is finished, the costs are over. It’s the opposite, once the project is finished, the life of the product begins, with continuous improvement .. or death), while operationals are unable to explain why they are so improductive, typically because of technical debt … Actually no one really understands each other world, and middle-managers try to take control on the debate with tons of cartography (ohh, look ! it would be so nice to merge these two application blocks, the titles say they do the same ..).

So we need a simple and comprehensive tool to better understand and discuss organizations IT assets – and liabilities, and take smarter decisions together: where to invest, on what, where to de-invest, etc.

OK, let’s get in : for each application in the system – we’ll call them product – we are going to measure 3 metrics : value, total cost of ownership (TCO) and technical debt. Then we’ll use a convention to display them as bubbles – rather than squares – to exhibit the fact that a system is not only a program, but a team of people as well. Team = Product.

While TCO can be measured quite precisely, we’ll see that we need to accept rough synthetic models for value and debt…

Value

Value should be measured from the end-user standpoint. Hence the value of this system is not the amount of money it has costed, but rather the answer to the question «what would we do if we no longer had it ?». Here the temptation of complex multidimensional modeling is often strong, especially among engineers : «we should aggregate the loss of not being in the market for x days plus one third of the damage on the brand, estimated as customer loyalty divided by …». Stop!

There is no «true value» to measure here. There is just an approximate consensus, which has its own value : everyone agrees on the importante (or unimportance) of this product.

So discuss the question «what would we do if we no longer had it?» again and again. Discuss between IT and end-users, and executives. Argue, propose simple, unidimensional models. And at some point, someone will suggest a synthetic approach that best represents what should be understood by everyone.

By experience, these synthetic models fall in two categories, depending on the asset being «front-office» or rather «back-office» :

– front-office assets, like a web store (Amazon, eBay, ..), are worth the revenues the company makes through them. Most of the time, if we don’t have them, this revenue will be lost. Value = revenues made through this chanel.

– back-office assets are different. If we loose them, we can still talk to our customers and make revenues, we just have to manually do what we used to do with the help of computers (accounting, control, inventory, purchasing). Imagine a solution that would only require spreadsheets and basic workforce, you always can! (look back 30 years ago if you lack imagination). Value = total workforce cost per year, because spreadsheets and data space are nearly free nowadays.

Now you have one figure in € or $. If you add all the values of your sub-systems, front and back-office, it can be greater than your company revenues, which just shows that IT is very important in your company (eMerchant, banks, telcos ..).

As end-user value is the most important thing to see, we’ll use it as the main scale of our diagram, it will give the surface of each product, like :

Total Cost of Ownership (TCO)

Costs of a system are not only the project costs or the maintenance costs, but include all what we shouldn’t have to pay for if we didn’t have this system: hardware, software, production staff, support staff. In typical IT departments, production teams are separated from development teams. While it is often easy to track development costs at a product level, you’ll have to do some analytical accounting in the datacenter, where things are more mutualised. Start basic, asking the question at your production staff («OK, so roughly, this application takes 2 thirds of this Unix server, which is managed by those 2 people for half of their time?»), and checksum that the sum of all production costs equals the production total budget, including managers, licences, datacenter, energy ..

Now to remain visual and comprehensive, we’ll use a shade of gray to display costs as a fraction of value. The darker the shade, the lower the ratio TCO/value : dark assets cost more than what they are useful, light assets bring more value than what they cost. In the middle, grey assets are neutral, we could decide to «decomputerize», it would be the same for the company.

Technical debt, a liability

How could we simply approximate the last metric of our cartography? Remember the goal: discuss, get a consensus on what should be done. The best way is to ask people in the field (developers, production guys..) : «what do you think we should invest to go back to a normal state of productivity? (a state where you are happy to maintain the code, where you no longer suffer from reccurent incidents, etc.)». You may have to ask several times the question as often, people that have lived for long in a decayed environment tend to think that it is normal, so ask again, «how much to transform this code into Open-Source or Google-class code that you would be proud of?». Then they will start to speak the truth and talk about their regular pains : technical obsolescence, lack of tests, data & code doublonning, code heterogeneity. Ask them the number of man-days required for a cleaning project, and valuate it in € or $.

We will then display this debt in €, as a fraction of the annual total cost, with a crust surrounding the asset. A crust visibly empeds an asset from developing, it is easily understandable by executives : bahhh big crust! ahhhh small crust! The thick crust on the right represents the equivalent of one year of costs of the asset (we should focus our entire energy for one year to clear it), a thin one, one tenth of the total cost (less than a month of the whole team to clean).

For products that are known to let their users very unsatisfied, it is a good idea to add the «end-user debt» as another contribution to the debt: how big a project that would produce all the features users have been complaining about for so long? I encourage you to be creative here : add it to the same crust or create another layer of crust with a different color…

Well, so where we go now? The cartography is not a goal in itself, it is a tool aimed at taking smarter decisions together, geeks, bosses and end-users. Imagine discussions with a result like this:

Or a discussion with your boss on something like this (more likely your situation …):

Now you must say, how to automatically build such a map? Just download this Excel tool I wrote, unzip the archive and start with the README. I distribute it under the GPL License so feel free to distribute and improve it.

Last, this cartography standard is evolving thanks to YOUR contributions. Help me. Comment. It should be improved, for instance by isolating variable costs from fixed costs at the production (datacenter amortization..), and probably many others learnt from experience.

Enjoy!