DesCOTS: A System for Selecting COTS Components

DesCOTS is a system that has an aim to help clients in the selection of COTS components. This system is based in the use of quality models associated to a software domain for evaluating the products in that domain, and for defining in a formal way the requirements of the clients for finding a suitable product in that domain. The evaluation and the formal definition of requirements are facilitated by metrics of each quality entity in the quality models. Our ISO/IEC 9126-1 based quality models are a set of quality entities structured in hierarchies of characteristics, subcharacteristics and attributes; with possible intermediate hierarchies of sub-characteristics and attributes.

DesCOTS is constituted by 4 subsystems. Two of them were presented in past RE conferences: QM, which supports the construction of quality models and EV, which supports the evaluation of products. In this conference we present SL that supports the definition of requirements and the selection of products. Finally, the system administration and the taxonomy construction and management is provided by the subsystem AD.

You can download the three client programs for DesCOTS-QM and DesCOTS-EV. Using the trial version of QM tool with username "user" and password "webuser" you can search a domain in our hierarchy of software domains, and browse the existent and validated quality models (i.e. Web Content Management, Versioning and Concurrent Control or Mail Server). In the case of EV, using the same username and password you can create the product evaluation corresponding to the domains of Web Content Management or Reference Management Tools. The manuals for using the tools can be found in manual DesCOTS-QM and manual DesCOTS-EV.

If you are interested in complete versions of DesCOTS-QM and DesCOTS-EV tools, just send us a mail message with your name, organization, e-mail address and postal address.

Non-technical criteria added in the Extended ISO 9126-1 quality model

Non-technical criteria such as administrative, economical or political are often significant in software selection, sometimes even more important than technical ones.
However, these criteria have not been included in most quality models proposals. Specifically, this occurs in the case of the ISO/IEC 9126-1 standard.
We proposed some time ago a hierarchy of 141 sub-characteristics and attributes that constitute an extension of this standard. These sub-characteristics and attributes decompose 3 high-level characteristics (supplier, business, and product), each one with its corresponding metrics.
Now this quality model extension can be consulted interactively by means of QMS tool. Here you have a capture of how this quality model is consulted through QMS.

Use of quality models in the selection of software products

The growing importance of commercial off-the-shelf software products requires adapting some software engineering practices, such as requirements elicitation, to this emergent framework. Also, some specific new activities arise, among which selection of software packages plays a prominent role. There are different types of requirements, such as managerial, political, and, of course, quality requirements. Quality requirements are often difficult to check. This is partly due to their nature, but there is another reason that can be mitigated, namely the lack of structured and widespread descriptions of product domains (that is, categories of software products such as ERP systems, graphical or data structure libraries, and so on). This absence hampers the accurate description of software products and the precise statement of quality requirements, and consequently overall product selection and confidence in the result of the process. Our methodology for building structured quality models helps solve this drawback.

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A new tool for look up quality models

Using the Quality Models Browser it is possible to navigate through our taxonomy of software domains. Browsing this taxonomy you may find the domains for which we have a defined quality model.

Once selected the domain in the taxonomy, it is possible to
look up the quality attributes of the quality model, their definition, their metrics (assignations), the relationships with other quality attributes, and if they participate in the definition of some requirement pattern.

New video for the current version of DesCOTS-QM

Clicking in the following figure, you can download a video where you may see the use of the taxonomy browser, the quality model manager, the definition of metrics and the creation of a requirement pattern.




In order to have a quicker access to the part of the video of your interest we have prepared an script of the video.

Poster of presentation of the DesCOTS System

Here you have the poster of presentation of the whole DesCOTS System, with especial focus in the selection of COTS components or products.

Information about DesCOTS-SL

Slides of the presentation of the tool may be find here.

Papers published:

• Carme Quer, Xavier Franch, Xavier Lopez-Pelegrin: DesCOTS-SL: A Tool for the Selection of COTS Components. RE 2006, Japan.