Metricas De Sw

The practical collection, acquisition and application of software metrics Peter R Hill Before we consider software measurement and collecting software metrics data, we need to ask ourselves: why are we doing this? Do organisations need data on their software projects and management? Does the I.T. industry need data about itself? I.T has become an important part of organisations’ strategy,competitive advantage and profitability. There is management pressure to build systems faster, better and at minimum cost. The return on investment that an organisation can get from the money it spends on I.T. has come under increased scrutiny from senior business executives and directors. Consequently I.T. now has to operate like other parts of the organisation, being aware of its performance and itscontribution to the organisation’s success and opportunities for improvement. How can I.T. executives achieve this without performance data? Flying blind is not an option. So what is it that managers need to know? Here are some of the questions that executives in the banking sector raised with me during discussions about the use of metrics in that sector: How do I know if my internal I.T. operationis performing satisfactorily? How do I decide whether I should outsource some or all of my I.T. operations? How do I know if my outsourcer is performing? What are the risk factors I should consider in an I.T. project? What questions should I ask to ensure that an I.T. project proposal is realistic? How do I know if a project is healthy? ie. what should I be worrying about? What are theinfrastructure trends for software development; languages, platforms tools etc.? And the list goes on. None of these questions can be answered without sound data. COLLECTING DATA – Organisational Level versus Industry Level Data As you can see, not all the questions involve benchmarking, there are many uses for an I.T. industry body of knowledge. Just imagine if the building and construction industry didn’thave a body of knowledge. How would that industry estimate project size? What would the quantity surveyors base their work on? How would they know if the quotations received were sensible? There can be no argument, the I.T. industry must have access to data, it must have its own body of knowledge. Having established that we need data, how do we go about collecting it? It would seem from thequestions listed above that there are two levels at which we need data; initially at organisation level and then at industry level, (with the ability to look at sub sets of industry data, by industry sector for example). If an organisation collects data about its own I.T. projects and builds a repository from this data, it can use it for macro estimation of future projects, it can do internalbenchmarking, track performance improvement, analyse what seems to work and not work in its operations and so on. This is a very good start, but many of the questions being raised by management go beyond the organisation itself. Before long there will be a need to benchmark against the world outside, estimate a project type that has never been done internally before or analyse the performance of otherlanguages and tools. For these we need industry data. In order for data to be useful, we have to be able to compare “apples with apples”, so it is important that the data collected at an organisation level can be compared to industry data. The obvious question is: What should I collect? Now this is the fun bit! If you ask your people what data they think you need to collect, the list will be

almostendless. If you then produce a questionnaire to collect all the data requested, the same people will wail: “I can’t collect and enter all that, I haven’t got the time or patience!” Data Collection Questionnaire The International Software Benchmarking Standards Group, (ISBSG), established its initial data collection standard over ten years ago. The Group constantly monitors the use of its data...