Research

Information and Software Technology 45 (2003) 539–546 www.elsevier.com/locate/infsof

Code and data spatial complexity: two important software understandability measures
Jitender Kumar Chhabraa,*, K.K. Aggarwalb, Yogesh Singhc a Department of Computer Engineering, National Institute of Technology (Deemed University), Kurukshetra 136119, India b Vice-Chancellor, GGS Indraprastha University, Delhi 110006, India c School of Information Technology, GGS Indraprastha University, Delhi 110006, India Received 5 October 2002; revised 22 February 2003; accepted 3 March 2003

Abstract In order to maintain the software, the programmers need to understand the source code. The understandability of the source code depends upon the psychological complexity of the software, and it requires cognitive abilities to understand the source code. The individual needs to correlate the orientation and location of various entities with their processing, which requires spatial abilities. This paper presents two measures of spatial complexity, which are based on two important aspects of the program—code as well as data. The measures have been applied to 15 different software projects and results have been used to draw many conclusions. The validation of the results has been done with help of perfective maintenance data. Lower values of code as well as data spatial complexity denote better understandability of the source code. q 2003 Elsevier Science B.V. All rights reserved.
Keywords: Code spatial complexity; Data spatial complexity; Understandability; Software metrics; Psychological complexity

1. Introduction In order to control, manage, and maintain software, the software complexity needs to be measured. If you cannot measure it, you cannot control it [7]. There are many aspects of the software. Some of them contribute towards the design and algorithmic complexity, some contribute towards readability and understandability of the software, and some other aspects have an influence

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