The Architecture of an Enterprise System

1
The Architecture of an Enterprise System
2
Objectives

• Introduce enterprise system architecture.
• Discuss system landscape.

3
Enterprise System Diversity

• Enterprise systems must run on a diversity of
  hardware and software platforms.
• Enterprise System Requirements
• Standard database technologies.
• Standard data communications protocols.
• Real-time support for key business processes
  throughout the organization.

4
Enterprise System Architecture

• Logical Architecture defines the components and
  functionalities supported by systems.
• The database is the heart of the logical support
  for integrated business processes.
• Physical Architecture defines how specific
  components are implemented on computer and
  communication systems.

5
Logical Architecture
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Logical Architecture

• The database contains operational data related to
  the realities of business transactions, including
  enterprise structure and environmental data.
• To support planning and analysis activities, a
  data warehouse is typically created as an
  additional database layer.

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Definition of Data Warehousing

• Inmons Formal Definition of DW
• A Data Warehouse is a subject-oriented,
  integrated, nonvolatile, time-variant collection
  of data in support of managements decisions.

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Operational Databases are Ill-suited as a Data
Source Supporting Discovery

• Traffic generated by accesses to organizational
  data to support data mining, DSS, OLAP, etc.
  negatively impacts organizational operations.
• Data required to discern the patterns of behavior
  within which discovery emerges is not retained in
  operational databases.

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Logical Architecture of R/3
FI FinancialAcctg.
SD Sales
CO Controlling
MM Materials Mgmt
PP ProductionPlanning
AM AssetMgmt
R/3
BASIS
PS ProjectSystem
QM Quality Mgmt
PM PlantMaint.
WF Workflow
IS IndustrySolutions
HR HumanResources
R/3 is the client/server system technological
tier for SAP that replaced R/2, the legacy
system version of SAP.
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Physical Architecture

• Database Layer.
• Application Layer.
• Presentation layer.

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Database Layer

• Typically a relational database distributed
  across multiple servers.

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Application Layer

• Application servers are responsible for specific
  applications stored as compiled versions of the
  application.
• Workload considerations may cause work to be
  rerouted to different servers e.g. multiple
  concurrently available application servers.
• Application servers retain application-specific
  data in caches to provide quicker access to
  recent versions of that data.

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Application Layer

• A work process defined for specific tasks help
  coordination between application servers.
• Application components supporting user
  interactive access bind to dialog work processes.
• Application components that generate background
  work bind to batch processes.
• Additional work processes coordinate activities
  between servers.

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Presentation Layer

• The purpose of the presentation layer is to
  accept essential data from the user and provide
  preformatted reports to the user.
• Presentation Layer Characteristics
• Provides the menu-driven GUI interface between
  users and applications.
• May reside locally on a users desktop computer
  or be a completely separate presentation server
  on the LAN.
• May keep in temporary, local storage a list of
  recently invoked transactions and data specific
  to the process being supported to alleviate the
  need to access the server.
• May be customized for a specific user.

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Open Systems Approach
ALE
OLE
EDI
RFC
CPI-C
TCP/IP
OLE Object Linking and Embedding RFC
Request for Comments CPI-C Common Programming
Interface for Communications ALE Application
Link and Execution EDI Electronic Data
Interchange TCP/IP Transmission Control
Protocol/Internet Protocol
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Tiered Configurations
Central system
Two
-
tier
Three
-
tier
Presentation
Presentation processes
Presentation processes
Application
Application processes
Database
Database processes
Database, application,
Database,
presentation processes
application processes
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3-tier Enterprise System Scalability
Presentation
Application
Scalability
Database
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Database Contains most objects
Database server
Organizational structure
Data dictionary
Log files
Transaction Data
Master Data
Programs
Application servers
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Application ServersContain work processes
Database servers
Application servers
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Application ServersContain work processes

• Work process can be
• Dialog
• Batch
• Update
• Spool
• Message
• Gateway

Message Server Coordinates message exchanges
between different application servers. Gateway
Server Allows the communication between R2, R3,
and external systems.
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System Landscape

• Attempt to isolate production system from
  development, testing, and training systems

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One System Landscape
Development
Development Testing
Quality Assurance
End User Training
Production
Sandbox
PRD
PRD Production
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Two System Landscape
Development
Production
Development Testing
PRD
Quality Assurance
End User Training
Sandbox
DEV
DEV Development PRD Production
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Three System Landscape
Quality Assurance
End User Training
Customizing Master
Development
QAS
Development Testing
Sandbox
DEV
Production
PRD
QAS Quality Assurance DEV Development PRD
Production
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Transport Management

• Version management.
• Import changes in an orderly manner.
• Apply changes consistently.

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Summary

• Introduced enterprise system architecture.
• Discussed system landscape.