軟體即服務（Software as a Service, SaaS）是雲端運算環境下一種新興的服務模式，它的特色是將特定的應用軟體以共享軟硬體資源的方式供眾多的租戶（tenants）使用。因此，如何提供共用且有客制化功能的應用軟體就是SaaS模式的重要成功關鍵。本研究聚焦於資料庫層提供多租戶共用表格但有客制化功能的機制。讓開發人員延續一租戶一資料表的架構為基礎設計資料庫，透過SQL語句轉換機制，將SQL語句轉換為操作共享表格的語句執行，以大幅減化開發人員的工作。本研究包含兩個部份，一是資料綱要對應表(Schema Mapping Table)，協助開發人員將單租戶資料庫架構轉換為塊狀表格(chunk table)的共用資料綱要方式；另一個是SQL語句自動轉換工具，透過剖面技術織入JDBC程式集中，在應用系統執行期間，將SQL語句，從一租戶一資料表寫法轉換為共享表格的方式執行。故只需將資料表改為共用架構即可使用，達到提升多租戶系統開發速度並提高資源使用率的目的。 / Software as a service (SaaS) is an emerging service model of cloud computing, which is characterized by providing software that charges on a usage basis over shared hardware and software resources for a large number of tenants to use. Therefore, how to provide shared tables and customization of the applications is an important key to success in the SaaS model. This study focuses on how to enable multi-tenancy on the database layer Developers can extend a private table structure-based application to a shared database one through the proposed SQL rewriting mechanism. This approach can greatly simplify the developer's work. Our approach consists of two parts, first is Schema Mapping Table that helps developers to convert single-tenant database architecture into the chunk table schema; another is SQL statement conversion tools that works by enhancing the JDBC library as an aspect in the AspectJ language. During the execution of the application, a SQL statement is rewritten from the private table based format into chunk table based statement. In this way, we are able to enhance an application with multitenant shared tables that improve resource utilization.

Dagens ökade krav på effektivisering och kostnadsmedvetenhet skapar behov av att enklare och mer affärsmässigt kunna anskaffa IT-stöd. Fler och fler företag på marknaden erbjuder sina kunder att köpa IT-stöd paketerat som tjänster levererade via Internet. FMV:s inriktning och strategi är att i allt större utsträckning köpa IT-stöd som tjänster då målet är att minska IT-kostnaderna. Problemet inom FMV är att arbetssättet och styrmodellerna inte anpassats till anskaffning av tjänster vilket resulterar i svårigheter att styra och följa upp avtal samt problem att dimensionera och planera IT-projekten. Arbetet inleddes med en förstudie för att kartlägga hur IT-enheten arbetar. För att tydliggöra problembilden och identifiera förändringsbehoven genomfördes en förändringsanalys som beskriver dagens svårigheter kopplat till visioner och mål. Utifrån framkomna mål och de visioner som legat till grund för inriktningarna för att minska IT-kostnaderna gjordes en analys av förändringsbehoven. Analysen påvisade att den inledande planeringen av IT-projekt är nyckeln för ett lyckat införande. För att åstadkomma en bra grund för projekten i planeringsfasen har en beslutsstödsmodell tagits fram. Modellen är baserad på faktorer som identifierats som kritiska i valet av anskaffningsstrategi och som i stor grad styr om ett IT-stöd kan anskaffas som tjänst. Kopplat till modellen finns påståenden kring anskaffning av tjänst och anskaffning i egen regi. Syftet är att skapa ett gemensamt resonemang så att projektledarna i olika IT-projekt utgår ifrån samma frågeställningar i planeringsprocessen. Som sista steg i planeringen skall en omvärldsanalys genomföras för att säkerställa att IT-stödet finns att tillgå som tjänst.

Small to Mid-size Enterprises (SMEs) typically are slow/late to adopt new technologies due to a conservative bias, cost factors and possible lack of knowledge. Implementation of a new Enterprise Resource Planning (ERP) system is a major, costly undertaking for a company of any size, especially SMEs, but there is the potential for huge paybacks touted by advantages afforded by the cloud. Cloud based ERP technology for SMEs is relatively new and poses a potential large risk-reward payoff. Given that these SMEs are currently functioning with their existing systems, why would they want to risk switching to "Bleeding Edge" Cloud ERP technology? Prior ERP research has focused primarily on an ERP’s implementation success and the relevant critical success factors (CSFs) important throughout the various stages of an ERP’s lifecycle. The focus of these studies has been on post-selection variables and the success or failure of the ERP’s adoption or implementation. Inherent in these studies are firms who already selected ERP technology which provides no insight into any potential barriers that prevent selection. ERP research in the area of SME cloud/SaaS ERP systems is nascent. This paper adds methodological, empirical and theoretical contributions to this existing stream of research about the motives and barriers in the selection of cloud ERP systems for SME’s. In particular, this research paper proposes to help bridge these gaps by operationalizing and testing Saeed, Juell-Skielse, and Uppström (2012)’s Unified Framework (UF) of the motives and barriers to the selection of cloud ERP systems. This current study uses Value Added Resellers (VARs) as subjects. They are arguably the most knowledgeable and in the best position to assess both the motives and more importantly barriers since there are in direct contact with the cloud ERP prospective purchasers.

abstract: Cloud computing has received significant attention recently as it is a new computing infrastructure to enable rapid delivery of computing resources as a utility in a dynamic, scalable, and visualized manner. SaaS (Software-as-a-Service) provide a now paradigm in cloud computing, which goal is to provide an effective and intelligent way to support end users' on-demand requirements to computing resources, including maturity levels of customizable, multi-tenancy and scalability. To meet requirements of on-demand, my thesis discusses several critical research problems and proposed solutions using real application scenarios. Service providers receive multiple requests from customers, how to prioritize those service requests to maximize the business values is one of the most important issues in cloud. An innovative prioritization model is proposed, which uses different types of information, including customer, service, environment and workflow information to optimize the performance of the system. To provide "on-demand" services, an accurate demand prediction and provision become critical for the successful of the cloud computing. An effective demand prediction model is proposed, and applied to a real mortgage application. To support SaaS customization and fulfill the various functional and quality requirements of individual tenants, a unified and innovative multi-layered customization framework is proposed to support and manage the variability of SaaS applications. To support scalable SaaS, a hybrid database design to support SaaS customization with two-layer database partitioning is proposed. To support secure SaaS, O-RBAC, an ontology based RBAC (Role based Access Control) model is used for Multi-Tenancy Architecture in clouds. To support a significant number of tenants, an easy to use SaaS construction framework is proposed. As a summary, this thesis discusses the most important research problems in cloud computing, towards effective and intelligent SaaS. The research in this thesis is critical to the development of cloud computing and provides fundamental solutions to those problems. / Dissertation/Thesis / Ph.D. Computer Science 2011

The thesis deals with the means of using cloud computing in business. The aim is to present the selected cloud services currently available on the market and then compare and evaluate them according to certain criteria. After the characteristics of the technology have been listed, including its advantages and disadvantages, a detailed description of the chosen products follows. Specifically, these are Microsoft Office 365, G Suite (formerly also known as Google Apps) and Dropbox Business. In the next section of the thesis, the services are evaluated in each of the selected criteria using the Kepner-Tregoe decision analysis. The list of the criteria includes, among others, the usability of the user interface, security, or deployment in a company.

Cílem diplomové práce je seznámit čtenáře s modelem ?software jako služba? (SaaS, Software as a Service) a popsat jeho vliv na dodavatelskou a uživatelskou stranu a na jejich produktivitu. Jelikož se na trhu objevuje stále více softwarových produktů a modelů jejich prodeje, měla by práce pomoci především uživatelům. Hlavním cílem je, aby čtenář po přečtení této práce získal jasnou představu o tom, co znamená termín ?software jako služba? a jaké služby v jakém množství jsou na trhu k dispozici. Práce je rozdělena do dvou částí. První poskytuje teoretický základ nutný pro pochopení poskytování aplikací formou SaaS, výběr vhodné metriky pro měření přínosů modelu a její použití v porovnání nákupu SW licence oproti outsourcingu SW. Autor se zde věnuje možnostem měření zvyšování produktivity organizace dosažené prostřednictvím IS/ICT, charakterizuje jednotlivé formy outsourcingu a popisuje souvislosti, které vedly ke vzniku ASP (Application Services Providing) a následně k SaaS. Hlavní přínos práce je v závěru první části, kde jsou popsány výhody a rizika spojená s modelem SaaS, která jsou doložena analýzou nákladů na aplikaci nasazenou formou outsourcingu a její porovnání s klasickým nákupem licence. Ve druhé části diplomové práce se autor zaměřil na popis jednotlivých aplikací, které jsou dostupné na trhu formou SaaS. Po důkladné analýze trhu vybral autor služby nabízené největším vyhledávačem Google a jedním z největších dodavatelů IS/ICT společností IBM. Právě velký význam těchto společností může mít značný vliv na další rozvoj modelu SaaS, v závislosti na úspěchu či neúspěchu jimi nabízených služeb a produktů.

The thesis deals with an analysis of approach methods, that can be used in integration of SaaS model applications into business information systems. To this end it presents business information systems. Description of these was performed from a general viewpoint. A description of what business information systems are was provided as well as a description of their architecture and service-oriented architecture. Business information sysstems were then described from a development/operation point of view, particular phases of the corelation between business and ICT were summed up, as well as ICT service supply models and development and operation alternatives. At the end of the chapter, a description of business information system components was performed. Services were described in the next chapter - first generally, with special interest in service characteristics and categorization. Furthermore I explored the concept of 'Anything as a Service' (XaaS), providing a summary of what can be provided as a service. Then a distribution model for Software as a Service (SaaS) was described along with its characteristics, parameters, benefits and limitations. At the end of the chapter cloud computing, its characteristics and models of implementation were described and the most notable providers were presented. The next chapter contains a description of integration and is targetted mostly on the description of system integration, on the system integrator as a person, on a description of technological means, usable in the integration itself. The next chapter is dedicated to a description of integration scenarios of business IS using SaaS applications. In the next chapter, an approach to the analysis of integration scenarios is defined, based on various viewpoints. The last chapter contains an assesment of particular integration scenarios and a consequential evaluation performed along evaluation criteria.

The target of the theoretical part is to provide an outlook in enterprising, describe optimal structure and a content of business plans and to give some recommendations regarding its elaboration. The practical part of this document includes the business plan elaborated by myself. This business plan describes an opportunity and business advantages of commercial providing IT infrastructure and hardware as a service. My goal is detailed description of essential elements of this enterprise, providing a market analysis, a customer targeting and an optimal resource planning. Furthermore I want to prove that the human resources planning is an essence even in the business with highly advanced IT technologies.

The thesis focuses on software piracy mainly in the context of cloud computing. Its goals are to analyze contemporary software piracy with the focus on its forms, reasons leading to it and on antipiracy techniques. Second part of the thesis defines cloud computing and focuses on two basic interdependencies with software piracy: cloud as a pirates' tool and cloud as means to fight the piracy. Based on the findings of previous parts, concluding part of the thesis suggests set of recommendations for involved parties (especially software providers, cloud service providers and cloud service users).

Cloud computing is a significant step forward in computer science. It enables customers to use applications on devices such as telephones, tablets, and computers over the internet. However, in the case of some applications, moving to the cloud can be challenging. Enterprise Resource Planning (ERP) is one example of such an application. ERPs need to be configurable since each company is different and has unique use cases. These configurations could be done by manipulating the logic and execution of programs by extending or modifying existing classes, basically writing customized plugins. The customer or the vendor could easily configure traditional offline single-tenant ERPs. Today, however, having this level of customization in a cloud-based multi-tenant ERP system is not an easy task. Since every customer shares the same application, though isolated from each other, changes made for one customer are made for every customer. Therefore, in this paper, we aim to find one or several answers to the question: how can you enable deep customization in multi-tenant SaaS systems in a secure way? A structured literature study is performed to analyze and investigate different solutions. The results gathered from the literature study showed that three solutions could be adapted: microservices, extensible programming, and static analysis tools. However, based on some requirements, extensible programming was found most suitable for the investigated ERP. / configurable, multitenant, SaaS, code,