問6
頻出度★☆☆
SaaS を説明したものはどれか。
平成21年度 春期 ITパスポート試験 問6
ストラテジ系システム戦略 › ソリューションビジネス
This question's explanation and your answers so far.
解説
問 6
Incorrectア
What is provided here is the use of computer equipment, that is, hardware and infrastructure such as servers, storage, and networks, not software functions. In the layers of cloud services this describes IaaS (Infrastructure as a Service), or a housing or hosting service that rents out data-center equipment and lines. Charging a usage fee is the same as in SaaS, but the user has to prepare and run the software themselves on the rented equipment, so the scope of what is provided differs from SaaS, where the user simply uses finished software functions.
Incorrectイ
This is a form in which part of the functions that a company's own information systems department has handled (system operation and maintenance, a help desk, and so on) is entrusted to an outside company, and a business outsourcing fee is paid in return; it describes outsourcing. The substance of the contract is having work carried out on your behalf, not a service that delivers software functions over the Internet to many unspecified companies in common. It also has nothing to do with which system the contractor uses, and unlike SaaS the fee is not determined by how much of the service is used.
- ウ
正解 The correct answer is ウ. SaaS stands for Software as a Service, one of the delivery models of cloud computing. Instead of selling the software product itself to the user, the provider runs and operates the software on its own servers and lets multiple companies or individuals use only its functions over the Internet, charging a usage fee according to the period of use, the number of users, or the volume of use. Users simply log in from a web browser or the like, so they do not need to buy or install the software themselves, nor build servers, apply version upgrades, or deal with failures. In addition, several companies share one system (multi-tenancy), so it costs less than preparing a dedicated system for each company, and it can be started quickly for just the number of users needed. Familiar examples include webmail, groupware, and online customer relationship management (CRM) or accounting services. Choice ウ, “it provides software functions as a service to multiple companies over the Internet and charges a usage fee”, states exactly these three points, namely what is provided (software functions), how it is delivered (the Internet), and how it is charged (a usage fee), so it is an appropriate description of SaaS.
Incorrectエ
This is a form in which users download the software onto their own devices and a license fee is charged in exchange for permission to use it; it describes the sale of packaged software (license sales by download). The Internet is used only as a distribution channel: the software runs on the user's own PC or server, and installation and version upgrades are the user's own responsibility. SaaS, in contrast, means using the functions of software running on the provider's side over a network, so the two differ fundamentally in whether the user keeps the software at hand.
ここがポイント
- SaaS (Software as a Service) is a cloud service that provides the functions of software operated by a provider to multiple users over the Internet and charges a usage fee. The key point is that users do not have to buy, install, or maintain the software, and can use just the functions they need for just the period and number of users they need.
- Cloud services are divided by the scope of what is provided into SaaS (software functions), PaaS (an environment for developing and running applications), and IaaS (infrastructure such as servers and storage). The key to judging is to identify what each choice offers as a service, and not to confuse it with outsourcing, in which work is carried out on your behalf, or with license sales, in which the software itself is handed over.
用語