1. System Engineering: Analysis And Design Chapter - 8

2. System Concepts Provides a meaningful framework for describing and understanding the features and functions of the subject. It is arranged with some logical governed by rules, regulations, principals and policies A system may have single input and multiple outputs or several inputs and outputs. Eg. Business System has several inputs and multiple objectives, such as sales, profit service and growth.

3. Cont…. The environment influences the choice of inputs, the method of processing, and the nature and contents of the outputs. InputProcessOutput Filter Environment Fig: Generalised Model of a System

4. Systems Control The device that measures the output is called a censor. Set the standard or norm of the output as an index of the system performance. The sensor measures the output and compares it with the standard. System provides a feedback to continue the operations.

5. Control System Model InputProcessOutput Sensor Comparison Unit Standard Corrective Unit Channels of Feedback

6. Cont… Info. Sys. are designed in a particular environment of business, industry and management. When the environmental factors or the input changes, the system is under a stress. Stress beyond a limit affects the other system elements which in turn affects the achievements of the goal. Unmanageable stress leads to a system failure

7. Control System Model for Data Processing Input Data Use of Program for Processing Computed Result Summary of Results Compare Results Desirable or Known Summary of Results Corrective Unit Feedback Change the program if Necessary ValidateData IfNecessary

8. MIS Model of Quality Assurance Date on Measures of Quantity Manufacturing Process Analysis of Quality Data One Measure of Quality Tools to Compare Quality Control Limits Corrective Unit Feedback Action to Correct the Process of Manufacturing

9. MIS and Support to Business System Components Business SystemMIS InputsRaw Materials, Plant and Machinery, Selling arrangements, Accounting Data from transactions of purchase, production and sales, receipts and payments Process Outputs Sensor Comparison Unit Standard Feedback Corrective Unit

10. Types of System System is defined and determined by its boundaries and objectives. Smaller systems together makes a large system and a large system can be split or decomposed into subsystems up to a certain level. The decomposition can be in a serial form or it could be in a matrix form. In any system the inputs are transformed into the output by the process. If the process of input transformation is not visible and understandable then we say that the system is a black box and the process is not transparent.

11. Subsystems in Serial Order Manufacturing good Subsystem 1 Quality Control Subsystem 2 Marketing good Subsystem 3 Subsystems Operating in Matrix Order Manufacturing good Subsystem 1 Quality Control Subsystem 2 Marketing good Subsystem 3 Accounting good Subsystem 4

12. Systems Classification Deterministic : When the Input, Process and Outputs are known certainly. –Eg: Accounting System. Probabilistic : When the Output can only be predicted in probabilistic terms. –Eg: Demand Forecasting System. Closed System : Functioning in isolation from the environment. Doesn’t have any exchange nor influenced by the environment. –Eg: Stock Management, Attendance System, Manufacturing System Open System : Systems which are required to respond to changes in the environment. –Eg: Marketing, Communication and forecasting system.

13. Handling System Complexity Factorization: –View the system as an assembly of subsystems, each with a clear definition of the boundaries, interfaces and their connectivity. –The subsystems then are put in the hierarchical order to provide a structural view showing the development path to the designer. Simplification: –Clustering the subsystems together. –Handling all the subsystems together with their interconnections.

14. Method of Simplification Identify the subsystems which have to be together for the functional ‘cohesion’. Form a cluster of these subsystems and identify interconnections in this cluster. Form a cluster of the remaining subsystems. Connect the clusters with an interface. –Eg. Material Management System

15. Material Management System A.Procurement System B.Purchase Order follow up System C.Receipts Accounting System D.Material Requirement Planning System E.Material issue requisition System F.Bill Passing and Payment System G.Inventory control System

16. Subsystems Interconnection ACDF B EG

17. Formation on Clusters on the Basis of Managerial Function A B F Cluster 1 Purchase Function C E D G Cluster 2 Stock Accounting Function Cluster 3 Material Planning and Control Function

18. Decoupling of Subsystems’ Cluster by Stock Information Interface A B F C E D G Purchase Information Stock Information