Small teams of senior people working on a well understood problems with known tools and little integration or dependencies on other applications do not need architects. This covers a significant proportion of line of business applications written today. However, there comes a point where cracks appear. There is no well understood threshold for a team size or a product’s complexity to require a software architect – no two individuals, teams, products or deadlines are the same, so what works well for one may not work for the other. However, there are four indicators or “smells” that a software architect is needed.
First, the product either lacks or does not meet non-functional requirements such as scalability, performance or security. Product Managers (PMs) or other customer advocates rarely articulate such requirements and, when they do, usually articulate them poorly or give them too low a priority. A software architect can balance the customer or business requirements with technical ones and provide the technical foundation to meet the customer requirements.
Second, the product lacks technical vision. Enterprise applications rarely exist in a vacuum. They need to integrate with other applications, often share components and need to lay the foundation to make likely future changes easier. Useful new components, frameworks or libraries may become available that allow the team to focus on business value and not solved problems, especially for older products (i.e. 10 years+). The industry may trend toward different platforms (e.g. mobile) or business models (e.g. cloud). Development teams are often too focused on the current release of the current product to take a step back and few others have the technical knowledge required, unlike a software architect.
Third, the development group has poor interteam communication and collaboration. Effective communication is easy for small teams of three to five people. This is much harder if the group has several hundred members in different continents and time zones. Effective cross team management may be difficult because individual team leads are usually focused on their own teams and the common management point may be a director or even an executive who has bigger problems on his or her mind and lacks the required technical focus. A software architect can divide the work and act as a coordinator between teams.
Communication with development teams outside the group is also critical. A development group often needs someone with broad rather than deep knowledge to evangelize their product(s) or identify integration points or sharable code. Once again, team leaders are usually too focused on their teams, directors are often too removed from the technical details and individual developers find the higher, longer term views too distant from actual code. A software architect usually has better communication skills, the right breadth of product knowledge and understands its technical vision. Similarly, non-technical but development-related teams like user interface designers, documentation writers or localization require someone with a broad technical knowledge and a customer focus.
Fourth, the group has unclear requirements or problem domains. Relatively few teams boast many subject matter experts or developers that use their software like their customers, particularly in junior teams, remote teams or those with a high turnover. PMs are often focused on dealing with customers or support issues rather than communicating detailed requirements to every developer. They also may not understand what the developers do not know and so provide too little or too detailed information. This process is also ongoing due to turn over and changing market conditions. Lastly, requirements also change as the project progresses, whether due to changing customer requirements, competitive landscape or just learning more about the problem.
These are traditionally areas where business analysts (BA) rather than software architects are used and can be used in tandem with a software architect. However, one exception is where business requirements may have unclear technical ramifications and feasibility, such a compliance with industry standards or regulations. Federal Information Process Standard (FIPS) 140-2 or Common Criteria require changes and documentation at many levels of detail which an architect is better suited to than a BA.
Note that software architects do not solve all problems with development. In particular, they highlight or exacerbate political or organizational problems when they try to bring stakeholders together or reconcile conflicting decisions and requirements. This may be intentional (to drive change) but is not sustainable in the long term.