Difference Between Loosely Coupled And Tightly Coupled Systems With Examples

What Is A Loosely Coupled System?

A loosely coupled system is an approach of interconnecting the components in a system or network so that each of its components has or makes use of little or no knowledge of the definitions of other separate components. The goal of a loose coupling architecture is to reduce the risk that a change made within one element will create unanticipated changes within other elements.

A loosely coupled system can easily be broken down into definable elements. The extent of coupling in a system can be measured by mapping the maximum number of element changes that can occur without adverse effects. Examples of such changes include adding elements, removing elements, renaming elements, reconfiguring elements, modifying internal element characteristics and rearranging the way in which elements are interconnected.

Loose coupling is mainly used in enterprise networks and systems to reduce the amount and intensity of risk found in highly dependent systems. A system with multiple components is less likely to have performance issues when those components are loosely coupled.

For example, in a client/server computing architecture, disconnecting the client from the server will result in the unavailability of some functions but the client will still be able to work independently of the server.

What You Need To Know About Loosely Coupled System

1. Loosely coupled systems have a distributed memory concept.
2. The interconnection network in a loosely coupled system is Message Transfer System (MTS).
3. Data rate of the loosely coupled system is low.
4. The loosely coupled system is less expensive but larger in size.
5. Loosely coupled system is efficient when the tasks running on different processors have minimal interaction between them.
6. Loosely coupled system is less expensive but larger in size.
7. They are widely used in distributed computing systems.
8. Throughput in this type of systems is low.
9. Power consumption is high.
10. Each process has its own cache memory.
11. Security is low in this type of systems.
12. It operates on multiple operating systems.
13. It has low scalability.
14. It has high delay.
15. Contention is low in loosely coupled system.

What Is A Tightly Coupled System?

A tightly coupled system is an approach of system design and computing where every hardware and software components are linked together in such a manner that each component is dependent upon each other. Tightly coupled system architecture promotes interdependent applications and code. Tight coupling is mainly used in enterprise systems and applications that work on the interconnectivity and inter-processing of two or more systems simultaneously to deliver a cohesive/integrated solution.

 In a tightly coupled system where multiple systems share a workload, the entire system usually would require to be powered down to fix a major hardware problem, not just the single system with the issue. For example, in a multiprocessing environment, where several computers share the workload, a tightly-coupled system might have to be shut down in order to add or replace one of the machines.

Typically, a tightly coupled system’s entire logic is distributed across several hardware and software components, which all need to be operational and connected to deliver the business logic/process. For example, a bank ATM machine depends on the ATM machine hardware, built-in firmware/applications and the primary banking application to allow a customer to withdraw cash or access any ATM-specific services. If any of these components is unavailable, the ATM will not work.  

What You Need To Know About Tightly Coupled System

1. Tightly coupled systems have a shared memory concept.
2. The interconnections in a tightly coupled system are Processor-memory interconnection network (PMIN), I/O-Processor interconnection network (IOPIN) and the interrupt-signal interconnection network (ISIN).
3. The data rate of tightly coupled system is high.
4. The tightly coupled system is more expensive but compact in size.
5. The tightly coupled system can take a higher degree of interaction between processes and is efficient for high-speed and real-time processing.
6. Tightly coupled system is more expensive but compact in size.
7. They are widely used in parallel processing systems.
8. Throughput in this type of systems is high.
9.  Power consumption is low.
10. System cache memory assigns processes according to the need of processing.
11. Security is high.
12. It operates on single operating system.
13. It has high scalability.
14. It has low delay.
15. Contention is high in tightly coupled system.

Also Read: Difference Between Positive And Negative Feedback In Control Systems

Difference Between Loosely Coupled And Tightly Coupled Systems In Tabular Form