Feature interaction is a
software engineering
Software engineering is a systematic engineering approach to software development.
A software engineer is a person who applies the principles of software engineering to design, develop, maintain, test, and evaluate computer software. The term ' ...
concept. It occurs when the integration of two features would modify the behavior of one or both features.
The term ''feature'' is used to denote a unit of functionality of a software application. Similar to many concepts in computer science, the term can be used at different levels of abstraction. For example, the plain old telephone service (POTS) is a telephony application feature at one level, but itself is composed of originating features and terminating features. The originating features may in turn include the provide
dial tone
A dial tone is a telephony signal sent by a telephone exchange or private branch exchange (PBX) to a terminating device, such as a telephone, when an off-hook condition is detected. It indicates that the exchange is working and is ready to init ...
feature, digit collection feature and so on.
This definition of ''feature interaction'' allows one to focus on certain behavior of the interacting features such as how their response time may be changed given the integration. Many researchers in the field consider problems that arise due to change in the execution ''behavior'' of the interacting features. Under that context, the ''behavior'' of a feature is defined by its execution flow and output for a given input. In other words, the interaction changes the execution flow and output of the interacting features for a given input.
Example
In the context of
telephony
Telephony ( ) is the field of technology involving the development, application, and deployment of telecommunication services for the purpose of electronic transmission of voice, fax, or data, between distant parties. The history of telephony is i ...
, a
telephone line
A telephone line or telephone circuit (or just line or circuit industrywide) is a single-user circuit on a telephone communication system. It is designed to reproduce speech of a quality that is understandable. It is the physical wire or oth ...
(the system) typically offers a set of features that include
call forwarding
Call forwarding, or call diversion, is a telephony feature of all telephone switching systems which redirects a telephone call to another destination, which may be, for example, a mobile or another telephone number where the desired called party i ...
and
call waiting
Call waiting is a telephone service where a subscriber can accept a second incoming telephone call by placing an in-progress call on hold—and may also switch between calls. With some providers it can be combined with additional features such ...
. Call waiting allows one call to be suspended while a second call is answered, while call forwarding enables a customer to specify a secondary phone number to which additional calls will be forwarded in the event that the customer is already using the phone.
To illustrate the example, we consider a telephone line provided to a customer, and we assume that both call forwarding and call waiting are enabled on the line. When a first call arrives on the line, the phone rings and is answered. Since neither feature is activated by the first call, there is no noticeable problem. When a second call arrives before the first has terminated, the telephone system has a decision to make: whether the call should be forwarded to the secondary number (call forwarding) or the person who answered the first call should be notified that another call has arrived (call waiting). Since this decision has no obvious correct answer, the optimal answer depends on the needs of the customer. This ''feature interaction'' is a specific example of a general and common problem that has become prevalent due to increasing system complexity.
In this situation, it is possible that the system’s decision will be made in a
non-deterministic fashion due to
race conditions
A race condition or race hazard is the condition of an electronics, software, or other system where the system's substantive behavior is dependent on the sequence or timing of other uncontrollable events. It becomes a bug when one or more of ...
and other design factors. The consequences of feature interactions can range from minor irritations to life-threatening software failures, and therefore there is ongoing research that aims to find ways of ''detecting'' as well as ''resolving'' feature interactions.
Workshops and conferences
*The series of Feature Interaction Workshops (FIW) and the International Conferences on Feature Interaction (ICFI) are the primary venues devoted to this problem:
{, class="wikitable" border="1"
, -
! Event
! Location
! Co-chairs
, -
, FIW'92
, St. Petersburg, USA
,
N. Griffeth, Y.-J. Lin
, -
, FIW'94
, Amsterdam, The Netherlands
, L.G. Bouma, H. Velthuijsen
, -
, FIW'95
, Kyoto, Japan
, K.E. Cheng, T. Ohta
, -
, FIW'97
, Montreal, Canada
, P. Dini, R. Boutaba, L. Logrippo
, -
, FIW'98
, Lund, Sweden
, K. Kimbler, L.G. Bouma
, -
FIW'00, Glasgow, Scotland
, M. Calder, E. Magill
, -
FIW'03, Ottawa, Canada
, D. Amyot,
L. Logrippo
, -
ICFI'05, Leicester, UK
, S. Reiff-Marganiec, M. D. Ryan
, -
ICFI'07, Grenoble, France
, F. Ouabdesselam, L. du Bousquet
, -
ICFI'09, Lisbon, Portugal
, S. Reiff-Marganiec, M. Nakamura
See also
*
Dependability
In systems engineering, dependability is a measure of a system's availability, reliability, maintainability, and in some cases, other characteristics such as durability, safety and security. In real-time computing, dependability is the ability to ...
External links
Research groups
Hybrid Feature Interaction GroupUppsala University
Papers
Pamela Zave
Pamela Zave (born 1948) is an American computer scientist now working at Princeton University. She is known for her work on requirements engineering, telecommunication services, and protocol modeling and verification, and is now working on network ...
.
Agents and their Services: An Ontological Approach to Feature Interaction
B. Cohen, City University.
E. Jane Cameron, Nancy D. Griffeth, Yow-Jian Lin, Margaret E. Nilson, William K. Schnure, Bellcore, and H. Velthuijsen, PTT Research, The Netherlands.
Conference proceedings
of FIW and ICFI a
IOS Press
Feature interaction: a critical review and considered forecast
M. Calder, M. Kolberg, E. H. Magill, and S. Reiff-Marganiec. Computer Networks 41, pp. 115–141 (2002).
Feature Interaction as a Context Sharing Problem
Armstrong Nhlabatsi, Robin Laney, and Bashar Nuseibeh. International Conference on Feature Interactions, 11-12 June, University of Lisbon, Portugal, pp. 133-148 (2009).
Software quality