SOCIAL_TECHNICAL_SYSTEMS AND SYSTEMS ENGINEERING.pptx

Deals with systems engineering

1. SOCIAL TECHNICAL SYSTEMS EXPLAINED PREPARED BY ; MUTIIBWA GRACE PETER BSC. SOFTWARE ENRGINEERING

2. Lecture Objectives Introduce the concept of STSs (Social Technical Systems) – That involves people , hardware and software and also discuss the “ relationship between Systems Engineering process and Social Technical Systems” Understand what STSs are ; and the difference between a technical computer based system and a social technical system.

3. Lecture Objectives Cntd Introduce the concept of Emergent System Properties – these include Reliability, Performance, Security and Safety likewise. Understand what activities are involved in the Systems Engineering Process. Understand why the organizational context (or setting) of a system may contribute or affect its design and usage .

4. Lecture Objectives Cntd Understand what legacy systems are, and also why they are usually business critical (extremely relevant) to the operation of many businesses.

5. LECTURE CONTENTS 2.1. Emergent System properties 2.2. Systems Engineering 2.3. Organizations, People and Computer Systems 2.4. Legacy systems

6. What is a System?? The word System is used every where and its in daily life used with; Computer Systems , Operating Systems , Payment systems ( also called Transaction systems) The Education System (Ministry and schools) The Government System (Its bodies and levels) General View : This means that any system has its own components that are working together ;

7. GENERAL SYSTEM DEFINITION A system is a purposeful collection of interrelated components that work together to achieve some objective

8. Detailed system meaning The above definition works for all systems in their categories like; A Pen contains – 4 hardware pieces or tiny components that make it function. An Air traffic Control System – has thousands of hardware, software components including humans who operate the system, and make decisions depending on the available information from the computer system

9. Systems with Software Our Focus : Systems that have software Components 1. Technical Computer Based Systems 2.Social Technical Systems

10. 1.Technical Computer Based systems These include software and hardware but not procedures or process Examples of such systems include; Televisions , mobile phones and most personal computer software A word processor used to write a book

11. 2.Socio-Technical Systems These Include one or more technical systems but , crucially, also ; include knowledge of how the system should be used to achieve some “ broader objective” E.g. A publishing system used to produce a book

12. Explaining Socio-Technica l Relate to the social aspect (people and society) and then the technical aspect of the society or organization. Thus Social Technical Systems ; refer to the Interrelatedness of the social and technical aspects of society or organization as a whole.

13. Growth of STSs 1.MECHANICAL LEVEL Computing began at this level, involved Hardware devices 2.INFORMATION LEVEL Evolved into this level that includes Hardware and software . 3.HUMAN LEVEL Evolved into this level that includes IT and Human Computer Interaction (HCI) . 4.COMMUNITY LEVEL Evolved into this level that includes people, software and hardware SOCIO-TECHNICAL SYSTEMS

14. Essential X-tics of STSs 2.Emergent properties depend on both the Components and the Relationships between them 1. They have emergent properties ; These are properties of a system as a whole rather than associated with individual components of the system.

15. Essential X-tics of STSs 3.They are often Non-deterministic ; In that when given specific input may not always produce the same output. 3.System behavior depends on Human operators ; and people don’t not usually react in the same way.

16. Emergent System Properties These are properties that appear only when all components of the system have been integrated. Emergent System Properties Functional - Emergent System Properties Non-Functional Emergent System Properties TYPES

17. Types Of Emergent Properties These appear when all parts of the system work together to achieve some objective i.e. a bicycle has the functional property of being a transportation device once it has been assembled from its components. These relate to the behaviour of the system in its operational environment. Examples are reliability, performance, safety and security. Functional Emergent System Properties Non-Functional Emergent System Properties

18. Examples of Emergent Properties Volume The volume of a system that is the total space it occupies varies depending on how the component assemblies are connected Reliability System reliability depends on Component reliability thus unexpected interactions can cause new types of failure of the system which affects the reliability of the system Security The security of the system( Ability to resist attack ) is a complex property that can not be measured.., attacks on the system can be devised, unfortunately these may have not been anticipated by the designers. Reparability Reflects on the ease with which system can be repaired when fault is discovered; That’s is ease in locating faulty component then repairing or replacing it Usability This is reflects on the ease with which the system can be used ; this depends on the technical system components and it operational environment

19. Reliability Property detailed Hardware reliability What is the probability of a hardware component failing and how long does it take to repair that component? Will the hardware wear out ? Software Reliability How likely is it that a software component will produce an incorrect output ? Note : Software failure is usually distinct from hardware failure in that software does not wear out . Operator reliability How likely is it that the operator of a system will make an error ?

20. Relationship between Systems Engineering and STS’s Systems Engineering; I s the activity of specifying, designing, implementing, validating, deploying and maintaining of Social Technical Systems ( STSs ). However Systems Engineering Comprises of a number of disciplines.

21. Disciplines that make up Systems Engineering. Systems Engineering Software Engineering Electronic Engineering Structural Engineering Mechanical Engineering Architecture User Interface design Electrical Engineering Civil Engineering Systems Engineering is an interdisciplinary activity that involves teams drawn from various backgrounds. These teams are relevant because wide knowledge is required to consider or identify all implications that may arise due to System design decisions made.

22. 2.3. Organizations, People and Computer Systems STSs are enterprise systems that are intended to deliver some organizational or business goal like; - Increase sales, -reduce material used in manufacturing, -collect taxes, -maintain a safe air space STss are designed such that the social system and the technical system work together such that new technology or system does not fail to meet the expectations of the designers and the users alike; Simply ; “Its all about people and technology or merely the interaction between people and technology in their work places”

23. Organizations, People and Computer Systems Therefore to understand the requirements of any social technical system , understanding the organizational environment comes first ; Thus there are human and organizational factors that may affect system design, these primarily include ; Process Changes Job changes Organizational changes

24. Does the system de-skill the users in an environment or cause them to change the way they work? If so the system may be resented, also if it involves managers scaling their work to fit the system the system will be resented likewise in that managers may feel that their status in the organization is being reduced by the system Human and organizational factors that may affect STSs design Process changes Does the system require manual changes to the work processes in the environment? I f so, training will certainly be required If changes are significant; if they involve people losing their jobs, there is a danger that the users will resist the introduction of the system . Job Changes Organizational changes Does the system change the political power structure in an organisation ? ;i.e. If an organisation is using a complex system, those who know how to operate the system have a great deal of political power .

25. Remarks; Therefore human, social and organizational factors are usually critical or extremely important in determining whether or not a system successfully meets its objectives. Unfortunately; predicting the effects of those factors on systems is very difficult for engineers with little experience in social or cultural studies

26. 2.4. Legacy systems Legacy systems are also socio-technical computer-based systems that have been developed in the past, often using older or obsolete technology; They normally have a long life span also called longevity These systems include not only hardware and software ; but also legacy processes and procedures —old ways of doing things that are difficult to change because they rely on legacy software

27. Legacy …Explained This normally relates to software or hardware that is outdated or old fashioned but can not be replaced because of its wide use. Simply ; This may mean software or hardware that people continue to use even though modern ones are present . Because of the time and effort spent to develop these systems, large computer based systems have a long life time ( longevity ) . i.e. Military systems, air control systems ( Are all designed to last many years )

28. Points to note; Legacy systems are often business-critical systems. They are maintained ( that is new features are added to add new functionality ) because it is too risky to replace them; i.e. for most banks the customer accounting system was one of their earliest systems. Organisational policies and procedures may rely on this system and are built around this system. Therefore: If the bank were to scrap and replace the customer accounting software (which may run on expensive mainframe hardware) then there would be a serious business risk if the replacement system didn’t work properly

29. PARTS OF A LEGACY SYSTEM AND THEIR INTERRELATONSHIPS Figure 2.11 depicts 6 components of a legacy system and how it works using its interrelated components. Their interrelationships are explained in detail below .

30. Legacy system Components System hardware In many cases, legacy systems have been written for mainframe hardware that is no longer available, that is expensive to maintain and that may not be compatible with current organisational IT purchasing policies Support software The legacy system may rely on a range of support software from the operating system and utilities provided by the hardware manufacturer through to the compilers used for development of the system itself; Again, these may be obsolete or (Out dated and old fashioned) and no longer supported by their original providers . Application software The application system that provides the business services is usually composed of a number of separate programs that have been developed at different times.

31. Legacy System Components Application data These are the data that are processed by the application system , In many legacy systems, an immense volume of data has accumulated over the lifetime of the system. This data may be inconsistent and may be duplicated in several files Business processes These are activities that are used in the business to achieve some business objective(s ) .Business processes may be designed around a legacy system and constrained by the functionality that the system provides. Business processes are limited to the functionality of the legacy system and thus should be built around its functionality. Business policies and rules These are definitions of how business should be carried out or ran and constraints on the business (simply restrictions or limitations) Note : Use of the legacy application system may be embedded in these policies and rules

32. Review Questions; 1. Explain why legacy systems may be critical to the operation of a business . Legacy systems are usually maintained other than replacing them because business risks may arise if the replacing system never performs as expected . 2. Explain why legacy systems can cause difficulties for companies that wish to reorganise their business processes; Legacy systems normally dictate the way business processes and polices are built since they are all built around the systems functionality .

33. THANK YOU