New-age Transactional Systems - Not Your Grandpa's OLTP
John Hugg discusses high volume transaction processing applications with high and low frequency profiles, and how VoltDB can be used for that purpose.
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Posted by Vikas Hazrati on Mar 16, 2010
Agile talks about small team sizes with the magic numbers of 7 plus minus 2. Agile also recommends whole teams. Whole team is a concept that recommends having sufficient skills within the team itself to get the job done. This implies that the development team has the requisite testing skills, database skills, user interface skills, apart from the core development skills. However, many organizations still struggle with questions related to the optimal team size and an efficient team composition.
Scott Ambler suggested that depending on the project needs there could be small Agile teams or large Agile teams. Small teams generally have the standard roles of Scrum i.e. A scrum master, development team and a product owner. The small team could also use a supporting cast consisting of technical experts like DBAs, domain experts and testers. A large team needs a 'team of teams' approach. According to Scott,
The typical strategy is to organize your larger team into a collection of smaller teams, and the most effective way to do so is around the architecture of your system. Each subteam should be responsible for one or more subsystems, enabling them to work as a small agile team responsible for delivering working software on a timely basis. This strategy is often referred to as Conway’s Law after Melvin Conway who introduced it in the late 1960s, and is one of several lean development governance strategies.
Steve Miller suggested that along with the Scrum recommended roles, he found it unrealistic for the team to handle quality assurance and documentation well. They improved the team composition to have 2 more roles. Software quality engineer to be responsible for the quality of a sprint and a Documentation specialist for creating user guides, administrative guides and training material.
Likewise, responding to a discussion on the Scrum Development group about team sizes, Michael F. Dwyer commented that
As Ron Jeffries may be otherwise occupied I will borrow his famous tag "2 + 2 = 5 with sufficiently large enough quantities of 2". Team size can be as small a 1 and as large as 500, it all depends on your definition of team and member involvement.
Thus there is a general consensus around the need to tweak the team sizes and composition as per the project needs. However, how do you validate that you have the most efficient team structure?
Mike Cohn suggested that answering the following nine questions and getting an affirmative response to each suggests a well structured team. His list of questions include
After answering the questions do you believe that you have an efficient team structure? What tweaks did you have to make to the Agile recommendations to arrive at your efficient team structure?
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It is certainly complex to create a well functioning team. There are several dimensions to this:
a) Many companies view QA as separate to development, and seem to think that you can't put the two 'types of people' together. The worry is that the 'sloppy developers' will 'corrupt' the QA people and the quality will be lower. Few seem to appreciate that the QA people are just as likely to influence the developers to better standards.
b) For large products it is often tricky to create suitably 'sand boxed' parts of the product to split it between teams and still maintain a global 'look and feel'. This is actually just as true with 'prince' or similar techniques as it is for scrum, but somehow we forget to remind people of this. In many ways scrum can be an advantage here, the product owners should get together to ensure a suitable global feel to the user stories - and to include sufficient detail in the user stories to ensure the API's and GUI across the system is reasonably consistent. In fact, I have seen a failure to ensure this cause masses of problems for Symbian and its customers - there is no consistency at all between different API's. They are not the only ones with the problem.
c)Many companies have developed a 'matrix management' structure, this does actually have its uses, but what it does lead to is a tendancy to move people from project to project to make best use of their current skills and avoid developing any new ones. Thus to keep a team together for the duration of one project, let alone to develop a scrum team over a number of years, is an uphill battle. Sure 'Fred' is needed for his architectural skills today, but surely you will have designed the architecture by Friday and I can have him for Joes project? We clearly understand that the architecture may change, that those skills, along with all the experience Fred had that led to him being considered an architect, are valuable throughout the project, it is especially valuable to the team to keep Fred involved as the project progresses so he can learn how well the architecture is implemented, and what its problems are
John Hugg discusses high volume transaction processing applications with high and low frequency profiles, and how VoltDB can be used for that purpose.
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