Little thought was given to how the software applications and systems we built were architected in the early days of software development. There were several reasons for this: firstly, software development is new, the concept hadn’t been thought of, and secondly, we didn’t realize how important architecture was to the cost of maintaining our applications and systems. Upon sober reflection, we probably should have foreseen the need for planned architecture and architects because building software isn’t radically different from building any other structure, for example, buildings and bridges. We can’t go back and undo the damage done by the lack of foresight that led to badly architected applications and systems. Still, as project managers, we can avoid making this mistake in our next software development project.
Today, most organizations whose core competencies include software development recognize the importance of architecture to their business. They have satisfied this need by creating the architect’s role and making this person responsible for the architecture of all the software applications and systems they develop. Even organizations whose core competencies don’t include software development but have invested heavily in IT have created this role. These people may be called the Chief Architect, Head Architect, or Strategic Architect. Wikipedia identifies three different categories of architects depending on the scope of their responsibilities: the enterprise architect, who is responsible for all an organization’s applications and systems; the solution architect, who is responsible for the architecture of a system comprised of one or more applications and hardware platforms, and the application architect whose responsibility is limited to one application. The category and number of architects will usually be constrained by the size of the organization and the number of applications and systems it supports. Regardless of what the organization you work for calls them, the software architect has a key role in your software project.
Now that you have a qualified software architect engaged for your project, you need to plan that person’s tasks to take maximum advantage of their skills. I recommend hiring the architect early in the project to influence the definition of the application or system being developed. The team that defines the business requirements for your project will be from the organization’s business side and have deep knowledge of how the business runs but little knowledge of the existing systems and technical features of the hardware and software that will deliver the solution. Having a software architect available during requirements-gathering exercises will help you define requirements that leverage existing system and solution platform strengths and avoid weaknesses. Leaving their input till a later phase exposes your project to the risk of re-engineering the solution to fit existing architecture or avoiding solution weaknesses after the fact. Involve the software architect in requirements-gathering exercises as a consultant or SME (subject matter expert) who can identify risks in defining requirements and offer alternative solutions.
The key deliverable your architect is responsible for is the architectural drawing. This is not a drawing but a mix of graphics and text. The pictures will represent the various components of the system and their relationship to one another. The reader will describe data elements, relations between different architectural elements, and any standards designers must adhere to. The drawing may be a new one to represent a new system, or it may be an update of an existing picture to reflect the changes to a current system made by your project. The development of the architectural drawing is the first design activity in your project schedule. The picture is used in the same fashion that engineering staff and skilled artisans use an architectural drawing of a building or bridge.
Analysts and programmers will use the Business Requirements Document (BRD) to tell them what features and functions to design. The architectural drawing means how their software must fit with other software, any constraints the system places on their design, standards the new software must meet, and what critical data elements look like. The information in this drawing will depend on the solution, hardware, existing system, and the project’s complexity. For example, projects using an Object-Oriented solution will have four layers: a user interface layer (the layer the user sees), an application layer (where the work is done), a domain layer (where business logic is applied), and an infrastructure layer (for logging messaging, etc.). Other solutions may call for more or fewer layers.
Software development projects that rely on a relational database to store and retrieve large volumes of data will have a database architect responsible for the design of the database. The database architect should be a member of your project team. Their design should be coordinated with the system architecture so that the data elements in the architectural drawing are defined the same way as they are in the database’s data dictionary. Database design is critical to system performance. Poor database design, or database design that does not support the applications using it will deliver a system with poor performance, so database design and architectural design must be inputs to one another to yield a well-integrated system with the performance characteristics required.
The project sponsor must approve the architectural drawing, the steering committee, and the organization’s enterprise architect/chief architect/head architect, where that person is not the architect on your team. In many cases, people other than another architect cannot determine whether the drawing contains all the information required by the project or whether the system design is sound. They will decide that each category of information has been addressed and that the drawing meets any requirements defined for it in the Project Charter, Statement of Work (SOW), or scope statement. Once the picture has been approved, it should be communicated to the analysts responsible for producing design specifications.
The software architect’s role does not end with the production of the architectural drawing; indeed, in some software development lifecycle (SDLC) methodologies, this drawing will be produced iteratively. It may be made in stages, such as the infrastructure layer first, the domain layer next, etc., or it may be made iteratively, with one new version for each iteration. Projects using the Waterfall SDLC methodology won’t necessarily make a final drawing during the project planning phase because they don’t need to. The designers need a picture that provides them with the information they need when they need it, and you may need to begin design work with the image you have to keep to the schedule.
The architect must also ensure that the design captured in Functional specifications and detailed design documents conforms to the constraints placed upon it by the architectural drawing. To do this, they must review the plans to determine compliance. The architect should be a member of any peer review teams studying the program. This may not be possible, especially if you have to share an architect with another project or operation. At a minimum, the architect should review each design and ensure compliance with their architectural design or identify gaps where it does not.
The hardware and operating systems, which are components of the system architecture, are areas of oversight for the architect. Projects that call for procuring these items or outsourcing the development of any applications should engage the architect to contribute to product and vendor selection criteria. Some architectural drawings may specify hardware and software depending on the solution being implemented, in which case the information should be included in the architectural drawing. Where requirements for these things are less well defined, the architect should ensure that selection criteria properly reflect their architectural needs and that the statement of work for any outsourced software is correctly written. In projects where software development work is outsourced, the architect’s role will be the same as if the work were done in-house. Large projects that require the vendor to staff their team with a software architect should have their architectural design overseen by the architect for your project.
Finally, the architect should also be called upon to analyze any changes to software design or functionality that could cause a difference in the architecture. Your architect will be the right person to investigate any request to determine where a difference in one system component’s design would impact other architecture components. Once the architect has decided if a difference in other members and the nature of that change would be required, it’s up to your design and builds gurus to assess the cost of that change.
