COTS and OSS: A Comparative View

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1 Volume 1, No. 12, February 2013 ISSN The International Journal of Computer Science & Applications (TIJCSA) RESEARCH PAPER Available Online at COTS and OSS: A Comparative View Jagdeep singh CSED, Thapar University Patiala, India jaggishergill47@gmail.com Shivani Goel CSED, Thapar University Patiala, India shivani@thapar.edu Abstract Open source software (OSS) and Commercial off the shelf (COTS) components are the most fundamental ways of software development. In this paper, COTS and OSS are compared on the basis of many attributes and development life cycle of software. Keywords- Commercial of the shelf (COTS), Open source software (OSS), Component based software engineering (CBSE) 1. Introduction The use of COTS and OSS in the software development is increasing at large extent [1][2]. OSS provides the code to the software developer for reuse and modification as per need. No cost is required to be paid for the software. COTS component can be used with the cost of purchasing and maintenance. Report shows that OSS surpassed their commercial counterparts in market share and quality evaluation [3]. Usually COTS are not provided with their source code which makes the OSS a strong competitor to COTS replacement. This paper is focused on OSS and COTS development life cycle and the key attributes that differentiate them. 2. Research Background The use of OSS in software industry has increased in last decade. 80% of the COTS components use OSS [4]. The OSS development mainly depends on welcoming any enthusiastic person to contribute for the project or its own idea. So the freedom of using OSS gives a lot more robust software [5]. In contrast to this, COTS components are developed using CBSE in much tight environment and they depend on component models like COM/DCOM [6], Enterprise Java Beans (EJB) [7], and CORBA Component Model (CCM) [8]. Software vendors usually develop COTS in a closed-source model. COTS are usually developed according to demand of market and usually targeted to earn profit. But in OSS, anyone that can write code is welcomed to join OSS to produce more good 2013, - TIJCSA All Rights Reserved 55

2 software product and can chose different business model. COTS usually use closed specification for its development and their license models are also subjected to the company policies. The development of OSS starts with welcoming any one to participate in the development process or join it. Since there can be multiple project developer that are scattered all around the world, there is a greater need of coordination and version control. There has been three type of license model proposed for OSS which are required to distribution of OSS. These are free, copyleft and general public license (GPL)- compatible [5]. In free license- the program can be freely modified and redistributed, in copyleft license - the owner gives private license, GPL-compatible-license are legally linked to GPL license structure. There are famous OSS packages and distributions like apache, red hat, linux distribution etc. The development life cycle of OSS is shown in figure 1. Fig1. OSS development cycle COTS based development introduces dependence on vendor, which ultimately influences development schedule, reliability and capability of the system [13]. The development process starts with the requirement analysis in which COTS selection is made on various requirements. Vendor s and customer s close interaction with the software team is essential. In the design parts, various interface requirements and glueware are identified. At this phase, system architecture is build. In the coding phase all the interfaces and glueware that are identified are implemented. After implementation, integration and testing is done and then system is delivered for use. Too much dependence on vendor is main factor that affects the success of the COTS development. The vendor decides when to update the COTS and also the COTS cannot fulfil the entire requirement, so there should always be a negotiation of requirement of the user. The user of COTS has to pay additional fees to vendor for its maintenance. The vendor can also retire its support for its COTS component, which is a serious concern for the user. The development process of COTS has been shown in fig , - TIJCSA All Rights Reserved 56

3 Fig2. COTS development process Key: Bidirectional flow and vendor, customer dependency Process flow Sub process 3. Comparison of COTS and OSS There are many attributes which are different in both type of components. In COTS, the tests done for certification and quality assurance are not known to the user, it is always kept under fold and it can be carried out only by blackbox testing[11]. But the OSS has changed this picture, and allows us not only to see the software product but also the implementation that do the work [12]. The source code of COTS is usually not provided and modification is purely dependent on the vendor. In contrast the source code of the OSS is available which makes it a strong competitor to COTS, so user can see all the processes and their implementation that are doing the job which make the development process much more transparent. While the license models of COTS are subjected to company policies and copyrights, OSS license models are categorised as- free, copyleft and GPL-compatible. In this paper, the COTS and OSS are compared on basis of quality attributes (maintainability, reliability etc.) and other attributes like standards, developer community support etc. The comparison is shown in table 1. Table1. Comparison of COTS and OSS Attributes COTS OSS Source code Not Available Available Modification Dependent on Depends on license model [5] vendor Field of endeavour (business, research) Restricted No restriction 2013, - TIJCSA All Rights Reserved 57

4 Standards Industrial standards like COM/DCOM, Enterprise Java Bean Limited access Open source standards like OMG s CORBA Access to developer Full access community Ease of maintenance Increase over time Decrease over time as software may goes through number of changes. Quality of Code Good Depends on motivation of OSS programmer Reliability High as industrial standards are followed Careful analysis required as OSS goes through a number of changes Vendor support Available Not available Distribution Free Paid License modelling Depends on Free, copyleft and GPL-compatible [5] company policies Certification Certified by vendor (COTS name- SRM 7.0 and vendor name- SAP public service) [14] No certification While the applicability of COTS and OSS is very vast, but we have shown the following examples of COTS and OSS in table2. Table2. Example of COTS and OSS Application type COTS OSS Office suits Microsoft office Star office Browser Internet explorer Netscape, Mozilla Database Microsoft SQL MySQL server, Oracle Web server Microsoft server Apache Interpreter Microsoft.net Java, perl 4. Conclusion The life cycle development of both COTS and OSS were compared. The comparison of COTS and OSS was done on base of various key attributes. OSS components are better than COTS as their source codes are available, which makes their testing and accessing the quality of the software easy. The reliability of OSS is difficult to predict or maintain due to changes in code while COTS components are reliable due to rigorous testing by vendor. Still as being freely available, the OSS software are most popular for use. 2013, - TIJCSA All Rights Reserved 58

5 References [1] Marchesin, Armand. "Using Linux for real-time applications." Software, IEEE, 21.5 (2004): PP [2] Paul Luo Li, Jim Herbsleb, Mary Shaw, "Forecasting Field Defect Rates Using a Combined Time-Based and Metrics-Based Approach: A Case Study of OpenBSD,"ISSRE (2005), PP [3] Wheeler D.A., Why Open Source Software / Free Software (OSS/FS)? Look at the Numbers! 2003, available at: [4] Access date jan 28, [5] Ming-Wei Wu, Ying-Dar lin, Open Source Software Developent: An Overview, Computer, 34(6): PP.33-38, June [6] Microsoft Component Object Model, Access date: jan 22,2013. [7] Enterprise Javabeans technology, Access date: jan 23,2013. [8] OMG, CORBA, Access Date: jan 24,2013. [9] Heineman G. and Councill W., Component-based Software Engineering, Putting the Pieces Together, Addison Wesley, [10] Grindal M., Offutt J., Andler S. F. (2005), Combination testing strategies: a survey. Software Testing, Verification and Reliability, 15, 3, PP [11] Spinellis, D. and C. Szyperski, How is open source affecting software development?, IEEE Software 21 (2004), PP [12] Stamelos, I., L. Angelis, A. Oikonomou and G. L. Bleris, Code quality analysis in open source software development, Information Systems Journal 12 (2002), PP [13] M. Morisio, et al., COTS-Based Software Development: Processes and Open Issues Journal of Systems and Software 61.3 (2002): PP [14] access date feb 2, , - TIJCSA All Rights Reserved 59