S. V. Subrahmanya

An Intelligent Procurement Marketplace forWeb Services Composition

In this paper, we present the design and implementation of a lightweight fault tolerance framework for Web services. With our framework, a Web service can be rendered fault tolerant by replicating it across several nodes. A consensusbased algorithm is used to ensure total ordering of the requests to the replicated Web service, and to ensure consistent membership view among the replicas. The framework is built by extending an open-source implementation of the WS-ReliableMessaging specification, and all reliable message exchanges in our framework conform to the specification. As such, our framework does not depend on any proprietary messaging and transport protocols, which is consistent with the Web services design principles. Our performance evaluation shows that our implementation is nearly optimal and the framework incurs only moderate runtime overhead.In this paper, we present the design and implementation of a lightweight fault tolerance framework for Web services. With our framework, a Web service can be rendered fault tolerant by replicating it across several nodes. A consensusbased algorithm is used to ensure total ordering of the requests to the replicated Web service, and to ensure consistent membership view among the replicas. The framework is built by extending an open-source implementation of the WS-ReliableMessaging specification, and all reliable message exchanges in our framework conform to the specification. As such, our framework does not depend on any proprietary messaging and transport protocols, which is consistent with the Web services design principles. Our performance evaluation shows that our implementation is nearly optimal and the framework incurs only moderate runtime overhead.

A Combinatorial Procurement Auction for QoS-Aware Web Services Composition

Business processes and application functionality are becoming available as internal web services inside enterprise boundaries as well as becoming available as commercial web services from enterprise solution vendors and web services marketplaces. Typically there are multiple web service providers offering services capable of fulfilling a particular functionality, although with different Quality of Service (QoS). Dynamic creation of business processes requires composing an appropriate set of web services that best suit the current need. This paper presents a novel combinatorial auction approach to QoS aware dynamic web services composition. Such an approach would enable not only stand-alone web services but also composite web services to be a part of a business process. The combinatorial auction leads to an integer programming formulation for the web services composition problem. An important feature of the model is the incorporation of service level agreements. We describe a software tool QWESC for QoS-aware web services composition based on the proposed approach.

A Survey of Enterprise Software Development Risks in a Flat World

The longer a fault remains in the code from the time it was injected, the more time it will take to fix the fault. Increasingly, automated fault detection (AFD) tools are providing developers with prompt feedback on recently-introduced faults to reduce fault fix time. If however, the frequency and content of this feedback does not match the developers goals and/or workflow, the developer may ignore the information. We conducted a controlled study with 18 developers to explore what factors are used by developers to decide whether or not to address a fault when notified of the error. The findings of our study lead to several conjectures about the design of AFD tools to effectively notify developers of faults in the coding phase. The AFD tools should present fault information that is relevant to the primary programming task with accurate and precise descriptions. The fault severity and the specific timing of fault notification should be customizable. Finally, the AFD tool must be accurate and reliable to build trust with the developer.COTS-based development and global delivery are two major disrupters in modern software development arena. Economic benefits offered by these disrupters cannot be neglected by organizations of any size. Unfortunately, alongside these benefits are several risk factors, which if ill-managed can cost the organizations both in terms of revenue and time. At Infosys, one of Indias leading software services organizations, built upon global delivery model we conducted a study by interviewing representatives from 23 projects to identify risks pertinent to COTS-based development in a global setting. We found 6 frequently occurring risks that will be summarized in this paper.

Optimal allocation of carbon credits to emitting agents in a carbon economy

Reduction of carbon emissions is of paramount importance in the context of global warming. Countries and global companies are now engaged in understanding systematic ways of achieving well defined emission targets. In fact, carbon credits have become significant and strategic instruments of finance for countries and global companies. In this paper, we formulate and suggest a solution to the carbon allocation problem, which involves determining a cost minimizing allocation of carbon credits among different emitting agents. We address this challenge in the context of a global company which is faced with the challenge of determining an allocation of carbon credit caps among its divisions in a cost effective way. The problem is formulated as a reverse auction problem where the company plays the role of a buyer or carbon planning authority and the different divisions within the company are the emitting agents that specify cost curves for carbon credit reductions. Two natural variants of the problem: (a) with unlimited budget and (b) with limited budget are considered. Suitable assumptions are made on the cost curves and in each of the two cases we show that the resulting problem formulation is a knapsack problem that can be solved optimally using a greedy heuristic. The solution of the allocation problem provides critical decision support to global companies engaged seriously in green programs.

Web services in the retail industry

It is a well-known fact that the retail industry always works on razorthin margins and the key to survival lies in optimization of resources both in space and time dimensions as well as maximization of customer satisfaction. Access to timely and even real-time information to a wide variety of channel and trading partners, sales personnel, line managers, store managers etc. is the key to achieving this. Web services technology holds out a lot of promise for the retail industry in this respect. It is a platform-neutral, easy to deploy set of standards for achieving business data and process integration, without going for proprietary point to point connections. It promises to connect the information providers and information consumers across a wide variety of platforms, devices and on an on-demand basis. Being based on service-oriented architecture (SOA) principles it can also form the enabling service interface layer for other emerging technologies like BAM, BPM, mobile and RFID. In this paper, we attempt to understand information-flow needs in the retail industry and also suggest a roadmap approach by which the retail enterprise could exploit the potential of web services at minimal risk.

Mechanism Design for Allocation of Carbon Emission Reduction Units: A Study of Global Companies with Strategic Divisions and Partners

The problem addressed in this work is concerned with an important challenge faced by any green aware global company to keep its emissions within a prescribed cap. The specific problem is to allocate carbon reductions to its different divisions and supply chain partners in achieving a required target of reductions in its carbon reduction program. The problem becomes a challenging one since the divisions and supply chain partners, being autonomous, could exhibit strategic behavior. We model strategic behavior of the divisions and partners using a game theoretic approach leading to a mechanism design approach to solve this problem. While designing a mechanism for the emission reduction allocation problem, the key properties that need to be satisfied are dominant strategy incentive compatibility (DSIC), strict budget balance (SBB), and allocative efficiency (AE). Mechanism design theory has shown that it is not possible to achieve the above three properties simultaneously. We propose two solutions to the problem satisfying DSIC and AE: (1) a reverse auction protocol and (2) a forward auction protocol, while striving to keep the budget imbalance as low as possible. We compare the performance of the two protocols using a stylized, representative case study.

Carbon footprint optimization: game theoretic problems and solutions

We discuss four problems that we have identified under the umbrella of carbon economics problems: carbon credit allocation (CCA), carbon credit buying (CCB), carbon credit selling (CCS), and carbon credit exchange (CCE). Because of the strategic nature of the players involved in these problems, game theory and mechanism design provides a natural way of formulating and solving these problems. We then focus on a particular CCA problem, the carbon emission reduction problem, where the countries or global industries are trying to reduce their carbon footprint at minimum cost. We briefly describe solutions to the above problem.

Incentive compatible green procurement using scoring rules

Green or sustainable procurement is critical to any supply chain in the modern era. In this paper, we address the issue of selection of suppliers in order to ensure that the procurement process in a manufacturing or service supply chain selects suppliers so as to minimize carbon emissions. The specific problem we address pertains to that of an orchestrator or a procurement planner who wishes to put together a green procurement network consisting of strategic suppliers. Our approach decomposes the problem into two stages. In Stage 1 (information elicitation), the orchestrator uses a green budget to offer appropriate incentives to the suppliers to report their carbon emissions accurately. The incentives are determined using an approach based on proper scoring rules. Having obtained emissions data in Stage 1, the orchestrator identifies a pool of suppliers in Stage 2 (green supplier selection) to minimize the quantum of carbon emissions of the procurement process. The paper focuses on Stage 1 of the problem and develops an incentive compatible mechanism for elicitation of emission estimates. We illustrate the proposed mechanism with a stylized example and also with detailed simulation results.

Mechanism design for green, truthful procurement auctions

Auction based mechanisms have become popular in industrial procurement settings. These mechanisms minimize the cost of procurement and at the same time achieve desirable properties such as truthful bidding by the suppliers. In this paper, we investigate the design of truthful procurement auctions taking into account an additional important issue namely carbon emissions. In particular, we focus on the following procurement problem: A buyer wishes to source multiple units of a homogeneous item from several competing suppliers who offer volume discount bids and who also provide emission curves that specify the cost of emissions as a function of volume of supply. We assume that emission curves are reported truthfully since that information is easily verifiable through standard sources. First we formulate the volume discount procurement auction problem with emission constraints under the assumption that the suppliers are honest (that is they report production costs truthfully). Next we describe a mechanism design formulation for green procurement with strategic suppliers. Our numerical experimentation shows that emission constraints can significantly alter sourcing decisions and affect the procurement costs dramatically. To the best of our knowledge, this is the first effort in explicitly taking into account carbon emissions in planning procurement auctions.

A strategy-proof and budget balanced mechanism for carbon footprint reduction by global companies

The problem addressed in this paper is concerned with an important issue faced by any green aware global company to keep its emissions within a prescribed cap. The specific problem is to allocate carbon reductions to its different divisions and supply chain partners in achieving a required target of reductions in its carbon reduction program. The problem becomes a challenging one since the divisions and supply chain partners, being autonomous, may exhibit strategic behavior. We use a standard mechanism design approach to solve this problem. While designing a mechanism for the emission reduction allocation problem, the key properties that need to be satisfied are dominant strategy incentive compatibility (DSIC) (also called strategy-proofness), strict budget balance (SBB), and allocative efficiency (AE). Mechanism design theory has shown that it is not possible to achieve the above three properties simultaneously. In the literature, a mechanism that satisfies DSIC and AE has recently been proposed in this context, keeping the budget imbalance minimal. Motivated by the observation that SBB is an important requirement, in this paper, we propose a mechanism that satisfies DSIC and SBB with slight compromise in allocative efficiency. Our experimentation with a stylized case study shows that the proposed mechanism performs satisfactorily and provides an attractive alternative mechanism for carbon footprint reduction by global companies.