Friday, 2 September 2016

System architecture and QA in management

As IT becomes a bigger part of everyone's business, so does system architecture and QA. Whenever we see a big IT project that fails, the cause of the failure often comes from having management that does not pay enough attention to system architecture and QA.

I think all readers of this blog have seen managers, that take decisions based on a typical project management approach, where physical meetings and physical hardware gets more attention than the architecture of the software, or the management methods required to generate good quality software. The most recent I heard, was an IT project manager who said: We just need to make it as good as we can. However, the IT system was meant to produce vital calculations for the owner, so "as good as we can" is, in my opinion, an unacceptable attitude. Either you do it right, or you report back that you cannot be sure to do it right.

The idea of project management is actually quite simple: Always make sure to tell people who does what when, and make sure it happens. That is where QA comes in. Most IT projects are too complex to make a project manager understand the details. So, in order to help the project manager, you should have a fairly detailed QA system for your software development. This QA system should cover planning of detailed design, source code maintenance, system maintenance and how to deploy it. In addition, there are many things that are hard to verify, so you should have a documented programming culture that explains how the programmers make detailed decisions, and remember to make sure, that your programmers know it, and report if they see violations.

All this must be required by the top management of modern companies. Also, there is often a lack of review of whether the architecture matches the business model, the business direction and possible future business directions. A business may want to keep its business model options open, and sometimes options are closed by system architect decisions.

Even when system architects or other design engineers come into the management, these processes are often forgotten or not executed properly.

One of the reasons why this happens, is because humans were not created for making perfect products, or following Quality Management Systems. The mathematical perfection, that is sometimes required to get everything right, collides with other skills that are also required to create great looking products, useful products etc. And system architects are often not good CEOs. So, in the end, it usually ends up being dependent on respectful, open-minded cooperation of a management team that really knows their stuff. Not all companies have that.

Sunday, 8 March 2015

35 years old Arduino-like setup with Pascal

I do not care much about products or constructions from the past, that cannot be reproduced or used, but in this case, my brother's old construction from the late 1970s made me look again, because it looks so much like what people do with Arduino kits.

This is a computer programmed using Compas Pascal or Turbo Pascal:


  1. CPU: Zilog Z80, of model Z80CPU01. This is probably running 1-2MHz. The Z80 was an extended version of the 8080 CPU, on which the 8086/8088/Intel CPU line of CPUs was built.
  2. One EPROM for the runtime
  3. One EPROM for the actual program
  4. 5x4 keyboard on the back, suitable to be used as a 4x4 hex keyboard with some more keys.
  5. Some RAM chips etc.
  6. I/O pins for easy access.
Unlike today, where we can program Arduino boards etc. using flash, easily, that kind of technology was unavailable or extremely expensive. Therefore, EPROMS were used, which could easily be erased using an ultraviolet lamp, and easily re-programmed using this board, which used the Centronics port for I/O to the programmer's computer, as USB was not invented back then.

The main computer, that was used for programming, could be a Zilog Z80 Nascom computer, a CP/M-80 computer, or any homemade computer that was using a 8080 or Z80 CPU.

Compas Pascal and Turbo Pascal were obvious choices for this, as the compiler was fast and generated great code, and therefore boosted programmer productivity a lot.

Wednesday, 7 January 2015

Test-driven programming guidelines

We all know about test-driven development. How many actually do this? Well, medical device software is made this way. Maybe the tests are not automated, but developers are required to establish verifiable requirements before starting to write source code. Since you only know if a requirement is verifiable, if you know the verification method, that means that you must know a verification method, i.e. test, before you can start programming.

Let's go one level up: What about programming guidelines? For instance, if your company has introduced the OOD methods mentioned on this page by Dr Bob, how do you verify that they are actually used?

Let's take one example: Derived classes must be substitutable for their base classes. How do we verify that this works? Well, first we need to find all classes that have been derived from another class, and then we need to verify that this class works in a test that works with the base class. We can usually find all class-derivations by scanning the source code, so scanning the source code would be part of the verification method. Next, we get a list of class names, and base classes, and we then must verify, that these classes are substitutable. This can be fairly easy on TStringList inheritance, but how do you verify that TXyzClass works instead of TAnotherClass? It quickly becomes a lot of work.

So, seriously, what if there is one part of the code that violates these programming guidelines, will you care? If you don't care, but you still want to verify compliance on each software release, then you need to mark this class as approved non-compliant so that you can skip it next time, and it does not show up on your error-list on the next product release.

Most people will probably end up saying: We do not verify that we are in compliance with this principle, as that would be too much work. It is only meant to be a guideline or principle... and if they are still ambitious, they might make random checks to measure compliance, and/or make senior developers review code from younger developers before the final commit. But that means that you cannot tell outsiders, whether you conform to the principles, or not. Instead, you can only be sure that you are not conform to the principles. You can only say that you try to be as much as possible.

To outsiders, this is vague information about what is going on in a software development department, which usually reduces the quality of communication to other parts of the company. So, you may want to ask yourself this question: What rules does your source code actually follow? Can you prove it?