Amol's Blog

As a person who has worked on software, in and out of corporate offices, a question was bound to come to me. What is the difference between software architecture and software design? The terms / designations are often heard in the context of software engineering. I think, this difference is worth exploring. It might throw some light on the subject of engineering, etc.

The term architecture can be found in the area of building construction, etc. So can be the term design. The design term is also used in the field of graphics, etc. As such, it is useful to consider these areas as well, because, it helps find answers to our question, it helps to refer to unrelated areas, in order to bring in new ideas as an answer into the current field of enquiry.

What is the difference between architecture and design?

The architecture, initially, brings to head, an image of some kind of diagram with blocks and connections between the blocks. The design, might bring up an image of some kind of document with some descriptions about some process, etc. This is a good place to start.

A question of this nature in mind and some YouTube videos later, an answer started to emerge. Some amount of thinking led to some concrete stuff for the answer.

The blocks and items found in the subject of software engineering are useful terms for the initial take. We can have two questions here. What is an architectural block? And, what is a design item?

These two questions, together, are possibly good enough to suffice as an answer for our question. If an element fits as an answer to the first question, it goes into the architecture and if it fits as an answer to the second question, it goes into design. A block, like, ‘Network’, or, ‘Storage’ fits well in the architecture, and, an item, like, ‘Compiler’, or, ‘Language’ fits well in the design. It can be reduced to deciding whether an element is a block or an item, a heuristic decision, in order to check whether it belongs to the architecture process or the design process. Then, one can proceed clearly, with a clear idea in the mind, about whether we are working on the architecture or the design. The two questions might suffice.

We are going to go ahead and drill down further, in order to differentiate between the two processes.

What does a software architect do? And, what does a software design person do?

It may not be necessary to find the answer to this question, but, it is an interesting exercise, which, might help inform ourselves in a completely unrelated area.

The basic difference is blocks and items. If an element in the software engineering can be represented as a block, then, it goes into the architecture process, otherwise, it goes into the design process. An element, like, ‘Network’ can be easily imagined as a block, so it goes into the architecture process, an element, like, ‘Compiler’ can be categorised, otherwise, as an item, so it goes into the design process. It might help, if one wants to distinguish between the two processes.

Then, something else also can be considered. How is the architecture, or, the design is communicated to the engineering team. I think, the architecture, with its blocks and connections suits well into the process of a meeting, with someone explaining the architecture briefly to the team of engineers so that it can be implemented. The design, on the other hand, with its description and possible diagrams, I think, suits well into the process of communication via a document or a diagram, a direct face to face contact with the engineering team may not be necessary. There goes our consideration of people issue.

Then, something more can be considered. What is a suitable representation for the architecture and one for the. design? Architecture, with the blocks and connections, might go well as a diagram. A diagram, a big one, with many blocks and connections between them will do good for the representation of an architecture. Design, with the description and diagrams might go well as a document. A document with many paragraphs and diagrams.

With the representation considered, one can come to the question of what tools to use for each of the processes? Architecture, with blocks and connections, can be done with any image making software, there may be thousands of them available. MS Paint, a free and easily available tool comes to the mind. Design, with description and diagrams, can be done with any document editing software, MS Word, widely used document editor can be used for the purpose.

So, we have considered not only the difference between the two processes, but, also, what representation and tools to use.

Next, we can even consider who suits well for each of the two processes, in terms of people. I think, the architecture, might fit someone who has a “thinking judgement” kind of process and the design, might fit someone who has a “intuitive judgement” kind of process. Architecture, as such can be thought of as a process based on memory use, and as such might involve thinking, more, much more than the design process. Design, on the other hand, can be thought of as a process which more of heuristic nature, and might involve more of “intuition”, than “memory”, an immediate and possible rough estimation of many things in the immediate surrounding. So, if one can categorise a person as fitting into one of these either types, one can put a person on the job of a software architect or the job of a software design person.

Next, I’ll go ahead and consider the other parameters for fitting a person into either one of the roles. It is the demography to which one belongs to. I think, that, a person coming from a smaller social construction might fit well as a software architect and a person coming from a very large social construction might fit well as a software design person. The reason can be explained. A person from a smaller social construction might have had a limited exposure to very large social groups and hence might be good at looking at things for longer periods of time. A person from a very large social construction, on the other hand, could be good at “intuitive judgement” owing to the fact that a very large social construction might involve a situation in which he/she is exposed to polar opposite types in a matter of half second and then back again. One has to stay on guard and judge extremely fast, thus, giving a sharpened edge to the faculty of “intuition”.

The parameter of geography can also be considered. As to, which part of the world a person must belong to, in order to qualify as a software architect or a software design person. I think, a look at the statistics of any search engine would help in this process. E.g. if a country has a large number of queries containing the term, ‘software architecture’, one can decide that, the people from the country are more inclined towards it, and if it is ‘software design’, then, it might be otherwise.

I have to admit, that, I have gotten a little crude here. But, then, this is not in the context of any organisation, like a university or a government, so, I am free to be crude.

There is more that can be considered. An element, like ‘External System’, might qualify well as part of the architecture, and, might be excluded from the design process. An element, like ‘Algorithm’ might fit well in the design process. An element, that comes up often, ‘Data Structures’, I think, might be excluded from the design process, and can be in the bucket of “use any”.

There is also the consideration of team. I think, that, the implementation team, the engineers can be completely separate from the architecture / design team, and, the architecture / design team can move on and/or work as a consultant to the implementation team. It may be obvious that a person with experience qualifies as an architecture / design team member. It may also be obvious that a person with no job qualifies as the one who does this kind of analysis.

With this, I can end this analysis of Architecture vs. Design question.