Management & Engineering 02 (2011) 1838-5745 Contents lists available at SEI Management & Engineering journal homepage: www.seiofbluemountain.com The SAAS Architectures and Design on the Five Layers Driving Model Guochun Tang * Department of Information, Oiongtai Teachers College, Haikou 571100, China K E Y W O R D S SAAS, SOA, Maturity model, Evaluation. SAAS architectures and design A B S T R A C T The traditional software architectures and design model cannot effectively solve some problems on SAAS ((Software as a Service) pattern, and guarantees the software product the quality. Therefore this article has carried on the discussion to the development process, the maturity model, the evolutionary process, and the pattern value chain's transformation of the SAAS, and proposed the SAAS architectures and design method based on five layers driving model. It can solve some difficulties in the SAAS software's complexity and the development process, and raise the SAAS software's development efficiency and quality well. ST. PLUM-BLOSSOM PRESS PTY LTD 1 Introduction SAAS (Software as a Service) is the progressive of software industry innovation in recent years. Overseas several big software giant Salesforce, SAP, Oracle, Microsoft have steped in the SAAS domain successively, the success based on SAAS pattern CRM (Client Relation Management) by Salesforce has winned the nearly 1,000,000 users the trusts as well as 95% customer success ratio, and by every year 80% speed sustained growth, becomed the successful model applying the SAAS pattern. Coming into the Chinese market with the overseas SAAS software, the domestic software business rapidly control strategy, joins in the SAAS profession. from the 800CRM thronejune, 2004, XTools, Jin Die, Yongyou, Alibaba, Digital China, CDC software, eabax software and so on promoted the SAAS pattern of the ERP system in view of the small and medium-sized enterprise informationization one after another forward. Carrying on the research on SAAS software development model and process have the very important value to developing the high performance and the SAAS software. This article has carried on the discussion to the SAAS architectures design method based on five layers driving model. It can solve some difficulties in the SAAS software's complexity and the development process. 2 The Development Process from the Module Programming, to Object-oriented, to SOA and SAAS The reusability of software has been following software's development process. SOA (Service Oriented Architecture) the appearance is not for the software programming, but decompose the business flow into the reusable sub-flow, make the reusability rise for the * Corresponding author. Email: tangguochun1@163.com English edition copyright ST. PLUM-BLOSSOM PRESS PTY LTD DOI:10.5503/J.ME.2011.02.011 61
design of the business flow layer, and shift software design's objective from the programmers to the business flow designers. The software development become into services' work, but no longer was the computer specialists' work. The SAAS refers to one kind of software business model (specially marketing pattern), but SOA refers to systematic realizes (including had system's conformity) the way, both originally is not on a concept level, but SOA has manifested the service conformity, the service agilely and so on numerous characteristics. These were precisely SAAS needs. The reusable mentality passed through to computer's software and hardware design and carried on the fusion, is the present clouding, SAAS is only the one kind of service form of clouding. The development process from the module programming to object-oriented, to SOA, and to SAAS is the available description under chart 1: Figure 1: The development process from module programming, to object-oriented, to SOA and SAAS Comparing with the traditional software, the SAAS service depends on the software and the Internet. characteristic prominent performance is: the Internet, the Multi-tenant, the service. Its business model's 3 SAAS Maturity Model and Evolutionary Process 3.1 SAAS maturity model SAAS is different in the traditional software requirement. it must be able to satisfy the different user, the different region, and the different service rule. SAAS request is high to the service compatibility, the extension, the flexible, thus also has the very high request to technology. Through the support of configurability, multi-user highly effective, the extendibility to SAAS application, may divide SAAS into four levels according to the maturity model. However, in the actual software development process, the mature SAAS application not necessarily simultaneously has these three characteristics. The architectures should be from the commercial request and the overall cost benefit, and chooses the appropriate SAAS model. SAAS maturity model is available to the following chart 2's description: Figure 2: SAAS maturity model for four levels 62
3.2 The process of evolution on SAAS software maturity model Based on the SAAS maturity model, the process which the SAAS software maturity model evolution evolves is as shown in. Figure 3. Figure 3: The process of evolution on SAAS software maturity model 3.3 The pattern value chain's transformation from traditional pattern to SAAS Under the traditional software development pattern, the customer constructing the IT system must face the software developer, the hardware provider, integrated business and the post-sale technical support directly, the system construction cycle is long, and the initial period invests is very much. Under the SAAS pattern, the customer only needs to have the connection with the provider to server, after ordering to serving the provider, the customer does not need to pay attention to system's software and the hardware, may use the service directly. From the traditional pattern to the SAAS pattern, the value chain changes from parallel transformation to serial transformation in the view of the customer. From the ASP pattern to the SAAS pattern, then presented the new value chain role to serve the provider. The SAAS pattern value chain's composition is as shown in Figure 4. Figure 4: The value chain's composition of SAAS pattern 4 The SAAS Architectures and Design Based on Five Layers Driving Model 4.1 The process model of Traditional architectures and design Using the iterate and increase thought of RUP, a classical architectures the design process model be composed by the analysis, the description, the choice, constructs and combines. Like Figure 5: Figure 5: The process model of traditional architectures and design with RUP This process model looked very smooth, but, as a result of SAAS complexity, it is very difficult to grasp its accuracy and reliability in designing. Moreover with its architectures system, the following design development is also very difficult to extensible. 63
4.2 The SAAS architectures and design based on five layers driving model The hierarchical analysis is the general method to solve complex question. During the software development process it has many levels, but regarding each level, the driving factor is also different. Therefore a better way is to discriminate and establish essential level, thus forms the hierarchical software architectures design model of the multi-factor driving.we make SAAS software architectures and design divide five layers-----the target layer, the configuration layer, the business logic layer, the realizing layer and the deployment layer At the same time, software's overall complexity also penetrates these five different abstract levels to obtain the clear portray. After introducing five layers driving models, SAAS architectures and design is as shown in Figure 6: Figure 6: The SAAS architectures and design based on five layers driving model In the model each layer has one kind of factor to drive its modeling design. The target layer driving factor is system's related role, the configuration layer driving factor is the each kind of goal of target layer, the business logic layer driving factor is the target layer and the configuration layer, the realizing layer driving factor is each kind disposable the request of the configuration layer and the business logic level. Using architectures technology, then realizes the high performance, expandable, and multi-tenant system request. The configuration layer's driving factor is the provider of the new value chain role serves. The following is carrying on the description to the part configuration factor of the configuration layer. The configuration for data : (1)custom-made the field: custom-made the field is according to the customer demand, increasing the corresponding field in the table structure to preserve the data custom-made (2) pre-assignment field: The pre-assignment field is referring to the preinstall certain amount field in the possibly expanded table, It permits user according to needs to assign the use. This reservation field does not 64
have the specific meaning. When the user proposed the data expansion demand, he may choose the corresponding field from the reservation field to satisfy the user's needs. (3) the name-value pair: The name -value pair is refers to saving the expansion data separately the name attribute and the value with an independent configuration metadata table and the expansion data table, it may commend the connection among the record table, a configuration metadata table, the expansive data table, and express the complete expansion data message. The configuration for function: (1) atomic function division: The function decomposition is that the overall system function should deference atomicity principle, and divide the most basic relatively independent atomic function taking the user value as the guidance. The atomic function is also the function configuration Fundamental unit. It has the following several characteristics: 1no-dividing. it requests to achieve as far as possible the refinement to system's function decomposition, guarantees the function configuration the flexibility. 2no-overlapping, the request is clear about each function the content and the function, when the division has the clear limits standard, the guarantee atom function relative independence. 3no-depending of circulate. It refers to the atomic function to be able to complete the complete service function through the limited order combination way. The inter atomic dependence is inevitable, but in the function decomposition process the circulation dependence is needs to cease. 4The overall integrity. It is all atomic function that can decompose and covers overall system's all functions, and does not have the system function which omits, particularly to some quite independent function. 5the value to customer. It is refers to the function to decompose must take the user value as the guidance. The atomic function takes the function configuration the Fundamental unit. It must provide the choice to the customer; request each atomic function to be able to bring some aspect to the user's value. (2) The design of function packet. It mainly embarks from tenant's profession characteristic as well as the business demand, to merit packet of function one step combination. It can fully satisfy the tenant to system function request, and enable the different tenant on demand use. According to the customer to function demand it may combine into the corresponding Mini version, the standard version and the full version. 5 Conclusion This article has carried on the discussion to the development process, the maturity model, the evolutionary process, and the pattern value chain's transformation of the SAAS, and proposed the SAAS architectures and design method based on five layers driving model. It can solve some difficulties in the SAAS software's complexity and the development process, and provide the quality of software product. Author in brief: Tang Guochun (1977-), male, software engineering master, the Hainan OiongTai teachers college,director of teaching and research section, CSAI consultant(csai031354), the system analyst, attains the IBM database 700,701 authentication, the main research area is: Software engineering (UML, CMM, MDA, SOA, SAAS and so on), clouding computation, computer education and so on. References [1]. Ye Wei Writing and so on. The Internet time's software revolutionizes the SaaS construction to design the [M]. Beijing: Electronics industry publishing house.2009. 26-128 (In Chinese) [2]. Lu Hong Chao.The ERP System Research Based on SaaS Model [D], Wuhan: Wuhan University of Science and Technology master's degree paper, 2009. (In Chinese) [3]. David Engelbrecht. SaaS Acceleration [J].OPSource SaaS Summit.2006.12 [4]. Zhang Lei Hu fei. Configuration Design and Realization in SaaS Application Rramework [J], the computer system application 2009 (6): 28-29 (In Chinese) [5]. Multi-Tenant data design pattern, http://www.ibm.com/developerworks/cn/webservices/ ws-multitenantpart4/index.html [6]. Software as a Service, http://msdn.microsoft.com/en-us/library/bb245821.aspx (In Chinese) [7]. CHEN Kang, ZHENG Wei-Min, Cloud Computing: System Instances and Current Research [J] Journal of Software,2009, 20 (09) (In Chinese) [8]. REST Style Service ISV Engagement standard, Alisoft Service Integration Platform, Technical white paper [R] (In Chinese) [9]. Microsoft clouding computation solution white paper [R], 2009.12: 30-35 (In Chinese) [10]. 2008-2009 The development condition white paper of China software operation service (SAAS) market [R] 10-50 (In Chinese) 65