I. INTRODUCTION System safety is a complex concept, which is represented by multiple attributes and which requires diverse sources of evidence to demonstrate its achievement. Safety-critical systems, which provide safety-critical services to their users, must be designed to be safe. This means that despite their complexities and despite variable environmental conditions, their operation should be demonstrably safety. A fundamental difficulty in measuring system safety arises due to the complexity of the notion – it is made up of multiple, potentially conflicting attributes, and difficult trade-offs may need to be made between these attributes. The attributes themselves are evaluated using multiple diverse sources of evidence, thus compounding the problem of measuring system safety. Software safety has become an ever increasingly important issue in system safety due to the larger role software plays in complex cyber-physical systems. Such a system is a consisted of a number of components distributed over a predefined space. Components of a typical cyber-physical system communicate with each other and with an external world through communication gateway. The safety failures of the components of such a system result in safety hazard of the whole system. Additionally, external attackers can attack the system through sensor network and communication gateway and can manipulate software processes and data stored and exchanged in the system. Over the last decades a good many number of safety analysis methods (i.e., FMEA, HAZOP, FTA) have been developed. Among them Fault Tree Analysis (FTA) [1] is a widely accepted method. It graphically shows how basic failures of components, in combination, cause a safety hazard at the system level.... ... middle of paper ... ...and System Safety Analysis”. IASTED’04. [4] J. Xiang, K. Ogata and K. Futatsugi. “Formal Fault Tree Analysis of State Transition Systems”. QSIC’05. [5] K. M. Hansen, and A. P. Ravn. “From Safety Analysis to Software Requirements”. IEEE Transactions on Software Engineering 24(7). 1998. [6] D. Coppit, K. J. Sullivan and J. B. Dugan. “Formal Semantics of Models for Computational Engineering: a Case Study on Dynamic Fault Trees”. ISSRE’00. [7] G. Schellhorn, A. Thums and W. Reif. “Formal Fault Tree Semantics”. WCIDPT’02. [8] W. Reif, G. Schellhorn, and A. Thums. “Safety Analysis of a Radio-Based Crossing Control System using Formal Methods”. IFAC’00. [9] B. Kaiser. “A Fault-Tree Semantics to Model Software-Controlled Systems”. Softwaretechnik-Trends 23(3). 2003. [10] B. Kaiser, P. Liggesmeyer and O. Maeckel. “A New Component Concept for Fault Trees”. SCS’03.
The Operating System (OS) is the heart of computer server and client systems; therefore they are the pivotal components of the Information Technology (IT) architecture. The OS contains the crucial data, information, and applications, which are vulnerable, and can be infiltrated to cripple the entire IT architecture of the organization. Therefore, it becomes mandatory to properly safeguard the OS from an internal or external intrusion (Stallings & Brown, 2012). This critical thinking report will highlight the security concerns that may impact the OS. Further, the security guidelines and best practices for the OS in general, along with the specific fundamentals regarding the Windows and Linux OS are comprehensively illustrated.
In the world today, computers are used in every field. Be it a major space exploration or a small chore like cleaning our room. The use of computers has made our lives easier but at the same time a computer failure can make our lives miserable too. We trust computers more than we trust anything else these days. We use computers to communicate, share personal information, buy goods online, etc. We also trust computers with our safety. Starting from house alarm systems and other safety devices we have now moved on to using computers to Test Car Crashes.
Sommerville, I. and Sawyer, P. (2000) Requirements Engineering: A good practice guide. Chichester: Lancaster University.
Technical Major Incidents occur when there are failures in technological systems. This could include faulty components of an airplane, defective rail tracks, radiation emissions, computer failures and many more and usually happen at any time without warning. For example – The Air France Flight 4590 Disaster (Concorde). Some causes of a technological major incident could include, faulty wiring, design flaws, wear and tear of materials, improper maintenance and many more.
Cyber security is the designing, creating, using, and repairing most technological and mechanical equipment. This includes programing and creating new technology before it is mass produced in order to insure safety and quality. It also cover the use of programs to protect and fix technological and mechanical equipment from malfunctions, viruses, and hackers. Lastly, cyber security includes the repairing and upkeep of most electronically designed systems. This job is important because most of today’s world is entirely made up of system that need to be protected, maintained, and constantly improved. This jobs needed in order to keep developed countries stable and able to keep developing,
...ial approaches which are Normal Accident and HROs, although it seems certain that both of them tends to limit the progression that can contribute toward achieving to highly protective systems. This is because the scope of the problems is too narrow and the potential of the solutions is too limited as well. Hence, Laporte and Consolini et.al., (1991) as cited in Marais, et.al., (2004) conclude that the most interesting feature of the high reliability organization is to prioritize both performance and security by the managerial oversight. In addition, the goal agreement must be an official announcement. In essence, it is recommended that there is a continuing need in the high risk organizations for more awareness of developing security system and high reliability environment in order to gain highly successful method to lower risk in an advance technology system.
If equipment flaw or a defective part is spotted, the damaged machine directly stops, and operators halt production and rectify the identified problem. It is essential ...
When it comes to safety most people think they are safe, and they have a true understanding on how to work safe. Human nature prevents us from harming ourselves. Our instincts help protect us from harm. Yet everyday there are injuries and deaths across the world due to being unsafe. What causes people to work unsafe is one of the main challenges that face all Safety Managers across the world.
When it comes to structural failure due to the collapse of a component, or a group of them, it refers to the deficiency of the part to withstand the stress of the workload for which it is designed. The components which an airplane is made of, are individually selected and thoroughly tested by manufacturers in such a way as to ensure safety standards of exceptional level.
It has been demonstrated that a number of interoperable systems must be implemented to fully protect a network; a strategy known as Defense in Depth. Due to the multitude of security devices and device categories available, it can be very difficult to identify the correct tools for meeting security goals. Using the Defense in Depth strategy will require an understanding of the interactions between devices occuring within the network.
Rajabalinejad, M. (2010). Bayesian Monte Carlo method. Reliability Engineering and System Safety, 95(10), 1050-1060. doi: 10.1016/j.ress.2010.04.014
A hazard is a potential damage, adverse health or harm that may effects something or someone at any conditions. Other than that, the risk may be high or low, that somebody could be harmed depending on the hazards. Risk assessment is a practice that helps to improve higher quality of the develop process and manufacturing process. It is also a step to examine the failure modes of the product in order to achieve higher standard of safety and product reliability. Unfortunately, it is common that a product safety risk assessments are not undertaken, or not carried out effectively by manufacturer. Mostly an unsafe and unreliable product was produced and launched on to the market. Thus, the safety problems are mostly identified after an accident happened or after manufacturing problems arisen. In order to prevent risk, a person should take enough precautions or should do more to prevent them because as a user should be protected from harm that usually caused by a failure for whom did not take reasonable control measures.
Leonard Lensink, 6 November 2013, Applying Formal Methods in Software Development, available from , accessed on 09 April 2014
Finally to conclude this report, the safety management system in an organization is very important as this forms the basic framework on how the organization works, maintaining safety. The four pillars (main objectives of SMA) are that ones that lead the organization in that direction. From the accident, the four pillars application will benefit the organization but however if the SMS has been a part of the organization even before, accidents as such would not have occurred in the first place.
Heinrich’s version of Domino theory was one of the earliest proposed Domino theory on accident causation model by W.H.Heinrich in 1931. He described accident as an multifactorial chain of discrete events and presented a series of dominoes and exhibit how series of dominoes topples simultaneously when one of them tumbles down. He proposed sequence of 5 factors that would prompt the next step of toppling the dominos lined up in a row (HW Heinrich, 1980). The sequence is 1.inju...