Module 3 - SAAS and PAAS

SaaS is defined as software that is deployed over the internet, licensed to customers on demand or through a subscription.
Characteristics of SaaS:
- Web access to commercial software
- Software is managed from a central location
- Software is delivered in a 'one to many' model
- Users are not required to handle software upgrades and patches
- Application Programming Interfaces (APIs) allow for integration between different pieces of software
Applications where SaaS is used:
- Applications with significant interplay between an organization and the outside world (e.g. email newsletter campaign software)
- Applications that require web or mobile access (e.g. mobile sales management software)
- Software used for a short-term need or with fluctuating demand (e.g. tax/billing software)

Multitenant SaaS is an architecture where multiple companies share the same instance to store their data, which is typically divided to prevent companies from accessing each other's information.
Benefits of multitenant SaaS:
- Hardware and power economy
- Effort to upgrade and backups and redundancy
Drawbacks of multitenant SaaS:
- Less customization and authorization
- Time delay
Single-tenant SaaS is an architecture where each company has its own instance of the software application and supporting infrastructure.
Benefits of single-tenant SaaS:
- Maximum privacy and workforce privacy
- Full use of system resources
Drawbacks of single-tenant SaaS:
- Costs of the whole system
- Inefficient use of resources

Open SaaS solutions are based on open-source code, web-based applications hosted, supported, and maintained by a service provider.
Examples of Open SaaS solutions: WordPress.com

SOA is a software architecture style that includes a collection of services in a network that communicate with each other.
Important principles of SOA:
- Service contract, autonomy, reusability, composability, loose coupling, discoverability, and statelessness
Benefits of SOA:
- Allows for effective changes according to market situations
- Keeps secret the implementation details of subsystems
- Allows interaction of new channels with customers, partners, and suppliers
- Authorizes companies to select software or hardware of their choice
Disadvantages of SOA:
- High investment cost
- Greater overhead when a service interacts with another service
- Not suitable for GUI applications

PaaS provides a platform allowing customers to develop, run, and manage applications without the complexity of building and maintaining the infrastructure.
Benefits of PaaS:
- Makes the development and deployment of apps simple and cost-effective
- Scalable and highly available
- Gives developers the ability to create customized apps without maintaining the software
- Greatly reduces the amount of coding
- Automates business policy
- Allows easy migration to the hybrid model
Disadvantages of PaaS:
- Lack of portability between PaaS clouds
- Resources constraints
- Dependency on network

SECaaS is a business model that offers security to IT companies on a subscription basis.
Working of SECaaS:
- Encryption: makes data unreadable until authentically decoded
- Network security: Network access management protocols to secure and monitor network services
- Email security: Protects against email frauds, spam, phishing, malware, etc.
- Identification: Users can access with a valid log-in ID and legal permission
- Data loss prevention: Tools are built to monitor and secure data to protect from data loss
Benefits of SECaaS:
- Provides superior security platform
- Lowers the total cost of ownership
- Offers the latest version of antivirus software
- Allows for cost-effective hiring of qualified security personnel
- Provides the finest service possible to secure the company's data
- Facilitates the IT team's ability to administer and monitor security procedures
- Faster delivery of security services
- Economical
- Log management can be outsourced to save time and money