Transcript Technology Background and Review

Technology Background and
Review
Daniel E. O’Leary
University of Southern California
c - 2000
Daniel E. O’Leary – copyright 2000
Technology Review
• In the analysis of ERP systems there are a number
of “technologies” that we will see … including
A. Client Server Systems
B. Networks
C. Relational Databases and Data Warehouses
D. Software
E. Software Choice
F. Reengineering and Best Practices
Daniel E. O’Leary – copyright 2000
A. Client Server
1. What is Client Server?
2. What is the basic notion behind C-S?
3. What is “Three tiered Architecture”?
4. Why concern with C-S?
– ERP generally are built for CS
Daniel E. O’Leary – copyright 2000
1. What is Client Server?
• Client Server is a computing model in which the
application processing load is distributed between
a client computer and a server computer, which
share information over a network.
• Typically the client is a PC running front end
software that knows how to communicate with the
server (often a db server)
• Typically the server is a PC or workstation, but it
can be a mainframe
Daniel E. O’Leary – copyright 2000
2. What is the basic notion
behind Client Server?
• Processing can be improved because client and
server share processing loads.
– Client - server computing says that the client has
computing power that is not being used
– Fundamental idea is to break apart an application into
components that can run on different platforms.
• Thin vs. Fat Clients
– A thin client has most of the functionality with server
– A fat client has most of the functionality with the client.
Daniel E. O’Leary – copyright 2000
3. What is a “Three Tiered
Architecture”?
• Three Tiered Architecture is an information
model with distinct pieces -- client,
applications services and data sources -that can be distributed across a network
• Client Tier -- The user component displays
information, processes, graphics,
communications, keyboard input and local
applications
Daniel E. O’Leary – copyright 2000
4. What is “Three Tiered
Architecture”?
• Applications Service Tier -- A set of
sharable multitasking components that
interact with clients and the data tier. It
provides the controlled view of the
underlying data sources.
• Data Source Tier -- One or more sources of
data such as mainframes, servers, databases,
data warehouses, legacy applications etc.
Daniel E. O’Leary – copyright 2000
Client/Server Configurations
Distributed
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Remote
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Application
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Daniel E. O’Leary – copyright 2000
Source: Gartner Group
B. Networks
• LANs, WANs, Intranets, Extranets
• Bandwidth
– Network Transmission Capability
• Standards
– TCP/IP
• Security
– E.g., Encryption
Daniel E. O’Leary – copyright 2000
C. Databases and Data
Warehouses
• Databases -- Numerous approaches
including relational databases
• Relational DB is a set of related files that
reference each other
• ERP are built on relational DBs and data
source in three tier is typically relational
• Data warehouse is a DB for decision
making, not transaction processing
Daniel E. O’Leary – copyright 2000
Salesperson #
Name
Address
Daniel E. O’Leary – copyright 2000
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Customer # Customer
Lastname
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Salesperson #
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O’Leary
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Sales Order #
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Customer # Salesperson #
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0001
Daniel E. O’Leary – copyright 2000
Lastname
Jones
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Sales Order #
Inventory #
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Amount ...
20
30
50
Inventory #
0001
0002
Daniel E. O’Leary – copyright 2000
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D. Software
• ERP have been developed for different
operating systems
– UNIX, Windows NT …
• Legacy Software
– Informally … software that has been in the
company for a while.
– Generally, developed in house
Daniel E. O’Leary – copyright 2000
Package Software
• In the same sense that personal computing
software has moved toward a standard set of
package options, corporate enterprise
computing has also moved toward packages
• Package software is changing the nature of
accounting, finance and IT departments
– No longer a matter of programming from
scratch, instead need to understand processes
Daniel E. O’Leary – copyright 2000
E. Software Choice
• Typically, use some form of cost benefit
analysis
– Benefits – fuzzy
– Costs – easily seen
• “As Is” vs. “To Be”
Daniel E. O’Leary – copyright 2000
F. Reengineering
1. What is it?
2. What are the primary approaches?
3. What is the role of reengineering in ERP?
Daniel E. O’Leary – copyright 2000
1. What is Reengineering?
• Process involves the redesign of business
processes to achieve dramatic
improvements in cost, quality, service or
speed.
– Typically involves transaction processing
– Tries to find inefficient rules of thumb built into
processes and break away from them
– Design business processes to exploit IT rather
than replicate old manual processes
Daniel E. O’Leary – copyright 2000
2. What are Primary Approaches?
• Two primary approaches: Start from scratch
and “Best Practices”
• Start from scratch and redesign processes
– Most expensive ... But considers unique aspects
of specific firm, processes, resources & people
• Using existing best practices generated by
others (e.g., consultants or competitors)
– Processes that have been proved in other firms
Daniel E. O’Leary – copyright 2000
3. What is the role of
reengineering in ERP?
• ERP have many best practices built into
them to choose from
– E.g., SAP now has over 1000 best practices
available to choose from
• Firms often use ERP as a way of
reengineering processes
Daniel E. O’Leary – copyright 2000