TOPIC 4: Integration and
Deployment
Topics:
• Components, interfaces and integration
• Infrastructure, Middleware and Platforms
• Techniques – Data warehouses, extending frameworks, wrappers, glue, facades
Core learning outcomes:
• Define integration in terms of components and interfaces.
• Give examples of middleware platforms.
• Discuss some advantages and disadvantages of some middleware platforms.
• Describe the major considerations for enterprise integration platform selection.
• Give an example of integration using the “wrapper”
approach.
• Give an example of integration using the “glue code”
approach.
• Give an example of how a framework facilitates integration of components.
• Explain how the data warehouse concept relates to enterprise information integration.
• Give examples of how testing and evaluation are impacted by integration choices.
SYSTEM INTEGRATION (SI) Definition
It is used for melding existing systems and new technologies to form more capable
systems that are intended to take on additional tasks, exhibit improved performance, and/or
enhance existing systems.
Definition 2
SI is a logical, objective procedure for
applying new and/or expanded performance requirements in an efficient, timely manner to the design, installation, and operation of an operational configuration consisting of
distinct modules (or subsystems), each of which may embody inherent constraints or limitations.
Key Terms
Logical, Objective Procedure. The SI process is clear to external observers and all steps have a built-in audit trail.
Efficient and Timely. The SI process will not be unduly burdened with delays that increase cost to the client and delay
deployment of the system.
Design, Procurement, Installation, and Operation. The SI process will be
employed throughout the entire process.
Key Terms…Cont…
Distinct Modules with Inherent Limits or Constraints. The concept of distinct
modules with inherent limits or constraints is central to the concept of SI. SI is
necessary when the configuration to be deployed includes devices with intimate connections to other devices previously deployed or to be deployed under a later procurement, particularly if these devices were designed and constructed by
subcontractors with only partial design
responsibility for the overall system.
Objectives of Systems Integration Methodology
1. To support problem understanding and communication between all parties at all stages of development.
2. Enable capture of design and
implementation needs early, especially
interface and interactive needs associated with bringing together new and existing equipment and software.
3. To support both a top-down and a bottom-up design philosophy.
Methods of integration
Vertical Integration
Horizontal Integration
Star Integration
Vertical Integration
Vertical Integration
This is a method which integrates subsystems according to their functionality by creating functional entities referred to as silos. The benefit to this system integration method is that theintegration is performed quickly and involves only the necessary vendors; vertical
integration is thus cheaper in the short term.
However, the cost-of-ownership involved is substantially higher than those in other
system integration methods..
Vertical Integration
This is due to the fact that, in case of new or enhanced functionality, the only way to
implement or scale the system would be by means of implementing another silo. Reusing subsystems to create functionality is thus not possible
Horizontal Integration
Horizontal Integration This is a method where a specialized subsystem is used for communication between other subsystems.
A horizontal integration system cuts the
number of connections/interfaces to only one per subsystem; this means the interface will connect directly to the enterprise service bus.
The enterprise service bus has the capability to translate the interface into another
interface. This allows for the integration costs to be cut, and also provides extreme
flexibility
Horizontal Integration
. It is thus completely possible to replace one subsystem with another subsystem through the use of a horizontal integration system.
Similar functionality is thus provided
although different interfaces are exported.
The rest of the subsystems can now follow by implementing the new interface between the enterprise service bus and the new
subsystem.
Star Integration
Star Integration (Spaghetti
Integration)This is a system integration
method where each system is interconnected to each of the remaining subsystems. When this method is seen from the perspective of the subsystem being integrated the
connections look like a star; however, when the overall diagram of the system is
presented, the different connections look like spaghetti.
The cost of the star integration system varies according to the interfaces which subsystems are exporting.
Star Integration
The integration cost can rise substantially in cases where the subsystems are exporting
heterogeneous or proprietary interfaces.
When adding additional subsystems, time and cost needed to integrate these systems show an exponential increase.
This system integration method often seems more preferable due to the extreme flexibility of the reuse of functionality.
SI Personnel Needs and Technical Areas
The client must define the SI requirements, specifications, constraints, and variables in a manner so as to provide the means for a SI
organization to deliver the necessary systems and services required to fulfill the client
mission under the specific contract
SI requires personnel who possess sound technical and management skills that
combine to provide the ability to integrate
technology and operations with technical and managerial direction.
Role of Systems Integration in Large, Complex Engineered Systems
Development and utilization of a strategic
plan for management and technical aspects of the program;
Establishment of a complete audit trail;
Assistance in meeting initially unrecognized needs (including changes in system
requirements);
Avoidance of under- and over-procurement;
and utilization of risk management plans;
Management of subcontractors to the same specifications as employed on the prime
contract; and
Provisions for future modification and expansion.
SYSTEMS INTEGRATION LIFE CYCLE
Requirements definition and specification
Feasibility analysis
System architecture development
Management plan: program and project plan
Systems design: logical and physical design
Implementation: design implementation, system tests, and operational deployment
Evaluation: system review and plan for replacement/retirement
Requirements Definition and Specifications
Definition of requirements by use
Review of requirements for ambiguity, conflict, and other issues
Development of systems specifications The goal for requirements definition and
specification is to completely define and correctly interpret the client's real needs.
Feasibility analysis
Determine the likelihood of successful system development and deployment
Examine new technologies
Assess risk and develop risk strategies
System Architecture Development
Describe functional system architecture
Specify required technical capabilities
Management Plan: Program and Project Plan
Identify technical architecture alternatives
Specify required configuration categories
Prepare program and project plans (e.g., work breakdown structure)
Prepare subcontractor management plan
Prepare risk management plan
Systems Design
Logical and Physical Design
Design approaches (e.g., top-down, bottom- up, etc.)
Use of CASE tools and other automated aids
Implementation
Design Implementation, System Tests, and Operational Deployment
Identify technical configuration
Specify required configuration component items
Procurement from subcontractors
Perform system tests
System deployment
SI implementation
Evaluation
System Review and Plans for Replacement~retirement
Review and evaluate system functioning
Obtain, install, test, and accept modified components
Maintain, modify, augment, and enhance systems
Plan for system retirement/replacement.
Functional Activities of Systems Integrators
Conduct general studies of needs to realize improved system performance.
Develop detailed specifications and designs.
Conduct risk studies and implement risk minimization strategies.
Perform system analysis and design.
Develop hardware and software design.
Employ project planning and control.
Perform business management and
accounting.
Functional Activities….. Cont..
Develop and nurture relationships with customers and subcontractors.
Develop hardware design and specification.
Carry out configuration management.
Accomplish testing.
Implement technology based solutions to business needs.
Train users of new systems.
Systems Integration Strategies for Success
For SI management, some of the strategies that will be necessary to compete in the SI world of the future include:
Strict control of overhead
Increased knowledge of client businesses
Proactive management to control costs and increase market share
Audit trails
The way to embed an audit trail in an SI program, either by the client or the SI organization, is to
i. Document system-level requirements into a database;
ii. Establish whether or not issues are present and, if so, resolve them;
iii. Assign appropriate validation and verification metrics;
iv. Establish guidelines for subcontractors;
v. Provide solid unambiguous procurement instruments; and
vi. Track these activities from specifications through installation and operation.
Quality Assurance in SI
Quality Assurance is a planned and
systematic pattern of all actions necessary to provide adequate confidence that the item or product conforms to established technical
requirements (IEEE)
Software quality is the degree to which the
attributes of the software enable it to perform its specified end-item use.
There is always need to define quality
attributes for the system, assess the affect of quality on system performance, and finally determine the metrics that are necessary for evaluation of quality.
Quality Assurance and Testing
Can be conducted from either a structural, a functional or a purposeful perspective.
Structural perspective, the system would be tested in terms of micro-level details that involve attributes such as hardware
processor input-output (I/O) lines, throughput capability, cycle time, and coding particulars.
Other quality assurance indicators would include system reliability, availability,
maintainability and interoperability or usability
Quality Assurance & Testing…
Cont…
Functional perspective, quality assurance and testing involves treating the system as a black box and determining whether the
performance conforms to the technical requirements specifications. And
Purposeful perspective, the system must be tested to determine whether it does what the client really wishes it to do. This is generally known as validation testing.
The Role of Verification and Validation
Software verification is the activity of
comparing the software product produced at the output of each phase of the life cycle with the product produced at the output of the
preceding phase. It is this latter output that serves both as the input to the next phase and as a specification for it.
Software validation compares the output product at each stage of the software life cycle, occasionally only the final product phase, to the initial system requirements.
Often these activities are performed by people outside of the software dev’t org
Middleware
Middleware is a general term for any programming that serves to "glue together" or mediate between two separate and often already existing programs.
A common application of middleware is to allow
programs written for access to a particular database to access other databases.
Computer software that provides services to
software applications beyond those available from the operating system.
Thus middleware is not obviously part of an
operating system, not a database management system, and neither is it part of one software application
Reading on
Advantages of using Middleware
Disadvantages of using middleware
Examples of middleware
Also on:
The tools and techniques for system
integration– Data warehouses, extending frameworks, wrappers, glue, facades
