Dynamic Consistency Checking Research Articles

E-AHP: An Enhanced Analytical Hierarchy Process Algorithm for Priotrizing Large Software Requirements Numbers

One of the main activities of software requirements analysis is requirements prioritization. The wrong requirements prioritization is risky as it leads to many software failures. The current requirements prioritization techniques can’t deal with large requirement numbers efficiently, which is considered one of their main issues. Many researchers have agreed that the analytical hierarchy process (AHP) is one of the best prioritization techniques as it produces highly accurate results. AHP has two main problems: scalability and inconsistency. These problems have motivated us to propose an improved version of AHP for software requirements prioritization, namely Enhanced AHP (E-AHP). A performance evaluation has been done for the conventional AHP, E-AHP, and one of the recent algorithms that also try to solve the AHP scalability problems, namely removing eigenvalues and introducing the dynamic consistency checking algorithm into AHP (ReDCCahp) algorithms The evaluation shows which algorithm takes the least time, uses the least memory, produces the most consistent and accurate results, and has the highest scalability. The three algorithms have been evaluated by running their codes using different numbers of requirements ranging from 10 to 500. The results show that E-AHP is more scalable, takes the least time, uses the least memory, and produces the most consistent and accurate results compared to the other two algorithms. That becomes remarkable when the number of requirements increases. Therefore, E-AHP is suitable to be applied in large software projects, as it can deal efficiently with the large software requirements numbers.

Instantaneous reaction-time in dynamic consistency checking of conditional simple temporal networks

Conditional Simple Temporal Networks (CSTNs) is a constraint based graph-formalism for conditional temporal planning. Three notions of consistency arise for CSTNs: weak, strong, and dynamic. Dynamic-Consistency (DC) is the most interesting notion, but it is also the most challenging. In order to address the DC-Checking problem, Comin and Rizzi [12] introduced ε-DC (a refined, more realistic, notion of DC), providing an algorithmic solution to it. Next, given that DC implies ε-DC for some sufficiently small ε>0, and that for every ε>0 it holds that ε-DC implies DC, it was offered a sharp lower bounding analysis on the critical value of the reaction-timeεˆ under which the two notions coincide. This delivered the first (pseudo) singly-exponential time algorithm for the DC-Checking of CSTNs. However, the ε-DC notion is interesting per se, and the ε-DC-Checking algorithm of Comin and Rizzi [12] rests on the assumption that the reaction-time satisfies ε>0; leaving unsolved the question of what happens when ε=0. In this work, we introduce and study π-DC, a sound notion of DC with an instantaneous reaction-time (i.e., one in which the planner can react to any observation at the same instant of time in which the observation is made). Firstly, we demonstrate by a counter-example that π-DC is not equivalent to 0-DC, and that 0-DC is actually inadequate for modeling DC with an instantaneous reaction-time. This shows that the main results obtained in our previous work do not apply directly, as they were formulated, to the case of ε=0. Motivated by this observation, as a second contribution, our previous tools are extended in order to handle π-DC, and the notion of ps-tree is introduced, also pointing out a relationship between π-DC and consistency of Hyper Temporal Networks. Thirdly, a simple reduction from π-DC to (classical) DC is identified. This allows us to design and to analyze the first sound-and-complete π-DC-Checking algorithm. Remarkably, the time complexity of the proposed algorithm remains (pseudo) singly-exponential in the number of propositional letters. Finally, it is observed that the technique can be leveraged to actually reduce from π-DC to 1-DC, this allows us to further improve the exponents in the time complexity.

Overcoming Scalability Issues in Analytic Hierarchy Process with ReDCCahp: An Empirical Investigation

Software requirements prioritization is considered a vital activity in developing software in order to reduce the risk of costly software failures. This research proposed a new solution for solving the scalability issues faced by the analytic hierarchy process (AHP) technique, namely removing eigenvalues and introducing the dynamic consistency checking algorithm into AHP (ReDCCahp). This aims to reduce the required number of pairwise comparisons, improving the efficiency and effectiveness of AHP. An empirical investigation was performed to evaluate the proposed solution, comparing ReDCCahp with the AHP. This comparison aims to show which of the two techniques is more scalable, more efficient, understandable, easier to use, less time consuming, needs less effort, and preferred by the participants in practice. A controlled experiment was carried out on a group of 84 participants who were asked to prioritize 42 requirements related to the online flea market system, using the two techniques in various orders. The experiment’s findings reveal that the participants using ReDCCahp had better ability to prioritize more software requirements (more scalable) with lower effort, shorter time, lower complexity, and higher understandability than using AHP. Furthermore, the participants preferred using ReDCCahp over AHP. The overall results confirm that using ReDCCahp is more effective and helpful than AHP and has the ability to solve the problems faced by AHP in prioritizing software requirements. Therefore, ReDCCahp is suitable to be implemented in real environments. This will contribute in helping software companies and related experts to enhance the quality of the proposed software.

Dynamic Consistency Checking in Goal-Directed Answer Set Programming

AbstractIn answer set programming, inconsistencies arise when the constraints placed on a program become unsatisfiable. In this paper, we introduce a technique fordynamic consistency checkingfor our goal-directed method for computing answer sets, under which only those constraints deemed relevant to the partial answer set are tested, allowing inconsistent knowledgebases to be successfully queried. However, the algorithm guarantees that, if a program has at least one consistent answer set, any partial answer set returned will be a subset of some consistent answer set.

Static and Dynamic Consistency Checking for Numerical Simulation: A Mixed-Logic and Object-Oriented Programming Approach

This paper presents a framework which implements common software functionalities. By using this framework, software designers focus on their activity in developing efficient data structures and algorithms. The logic programming introduced in this framework is an efficient technology for Object Constraint Language expressions. Errors made by the user when modeling a device are detected and prevented by the modeling guide.