Four Software Development Methodologies Free Essays

Student Name Student ID Student Signature Assessor Name Assessor’s Signature Final Result / Grade Assessed By / Date Case Study Research (worth 20% of final grade)100 MarksSOF535: Application Design and DevelopmentVersion 1.1, Level 5, Credits 20New Zealand Diploma in Information Technology Technical Support Level 5Task 1: Requirement Gathering and Analysis(Total 40 Marks) comparison between four software development methodologies. Four Software Development MethodologiesWaterfall Development MethodologyThe Waterfall approach to systems analysis and design was the first established modern approach to building a system. We will write a custom essay sample on Four Software Development Methodologies or any similar topic only for you Order Now This method was originally defined by Winston W. Royce in 1970, (â€Å"The Waterfall Development Methodology†, 2006). It quickly gained support from managers because everything flows logically from the beginning of a project through the end, (Jonasson, 2008). Sources differ when it comes to the specific steps in the Waterfall process. Rapid Application Development Methodology Rapid application development is a software development methodology that uses minimal planning in favor of rapid prototyping. A prototype is a working model that is functionally equivalent to a component of the product.In the RAD model, the functional modules are developed in parallel as prototypes and are integrated to make the complete product for faster product delivery. Since there is no detailed preplanning, it makes it easier to incorporate the changes within the development process.RAD projects follow iterative and incremental model and have small teams comprising of developers, domain experts, customer representatives and other IT resources working progressively on their component or prototype.The most important aspect for this model to be successful is to make sure that the prototypes developed are reusable. Agile Development Methodology There are many different forms of the  Agile development method  including: Scrum, Crystal, Extreme Programming (XP), and Feature-Driven Development (FDD).  Agile methods  attempt to minimize risk (such as bugs, cost overruns, and changing requirements) by developing the software in iterations that  are mini-increments of the new functionality. The benefit of multiple iterations is that it improves efficiency by finding and fixing defects and expectation mismatches early on.Agile methods rely on real-time communication, which fails to provide new users with documentation to get up to speed. They require a huge time commitment from the users, and is labor-intensive on the developers due to the need to fully complete each feature within each iteration for user approval. The benefits to the software are realized early on due to the incremental addition of the iterations. The Agile methods are similar to RAD, and  can be inefficient in large organizations. Programmers, management and organizations accustomed to the Waterfall Method may have difficulty adjusting to Agile, and often a hybrid approach works well for them. DevOps Deployment Methodology DevOps deployment  is centered around organizational change that  enhances the collaboration between the departments responsible for different segments of the development life cycle, such as development, quality assurance and operations. It is focused on improving the time to market, lowering the failure rate of new releases, shortening the lead time between fixes, and prioritizing minimal disruption as well as maximum reliability. To achieve this, DevOps aims to automate its continuous deployment to ensure everything happens smoothly and reliably.Companies that use  DevOps  have benefitted by significantly reducing the time to market, improving customer satisfaction, improving product quality and improving productivity and efficiency of its employees. A few  drawbacks of DevOps includeappropriate methodology that is suitable for this project.It totally depends on the nature of the project. Many people might argue that Agile is the best methodology for software development and it does have significant advantages in most cases; however, saying â€Å"Agile is better than Waterfall† is like saying â€Å"A car is better than a boat†. They both have advantages and disadvantages depending on the environment.Agile/Scrum works best with projects that have high levels of uncertainty and require an adaptive approach. A plan-driven approach (what many people loosely call â€Å"Waterfall†) works best in situations where the requirements are fairly certain and there is some need for predictability of project costs and schedules. And, of course, that is not meant to imply that there is a binary and mutually-exclusive choice between two extremes. There are many ways to blend an adaptive (Agile) approach with a plan-driven approach in the right proportions to fit the situation.There is no â€Å"silver bullet† methodology that fits all possible projects and the right solution is to fit the methodology to the nature of the problem rather than force-fitting a project to some predefined methodology.https://blog.blackducksoftware.com/top-4-software-development-methodologiesTwo types of requirements1.Functional Requirements Functional requirements define the fundamental actions that system must perform.The functional requirements for the system are divided into three main categories, Reservation/Booking, Food, and Management. For further details, refer to the use cases.EXAMPLE 1.Reservation/BookingThe system shall record reservations.The system shall record the customer’s first name.The system shall record the customer’s last name. The system shall record the number of occupants.The system shall record the room number.The system shall display the default room rate.The system shall allow the default room rate to be changed.The system shall require a comment to be entered, describing the reason for changing the default room rate.The system shall record the customer’s phone number.The system shall display whether or not the room is guaranteed. The system shall generate a unique confirmation number for each reservation.The system shall automatically cancel non-guaranteed reservations if the customer has not provided their credit card number by 6:00 pm on the check-in date.EXAMPLE 2FoodThe system shall track all meals purchased in the hotel (restaurant and room service). The system shall record payment and payment type for meals.The system shall bill the current room if payment is not made at time of service.The system shall accept reservations for the restaurant and room service. Management The system shall display the hotel occupancy for a specified period of time (days; including past, present, and future dates).The system shall display projected occupancy for a period of time (days).The system shall display room revenue for a specified period of time (days).The system shall display food revenue for a specified period of time (days). The system shall display an exception report, showing where default room and food prices have been overridden.The system shall allow for the addition of information, regarding rooms, rates, menu items, prices, and user profiles.The system shall allow for the deletion of information, regarding rooms, rates, menu items, prices, and user profiles.The system shall allow for the modification of information, regarding rooms, rates, menu items, prices, and user profiles.The system shall allow managers to assign user passwords. How to cite Four Software Development Methodologies, Papers

Nas †“Illmatic” free essay sample

Nasir Jones, known as Nas, is one of the greatest emcees of all time. His albums are considered classics by many hip-hop critics. This political artist uses his knowledge of the world to incorporate intelligent lyrics in his work. Nas is well respected by other rap artists – and rightfully so. He has blessed listeners with his work for over 10 years. Nas’s most influential album is a gem titled â€Å"Illmatic.† From the production to the beats to the lyricism, everything is well constructed and polished. The best song in my opinion is â€Å"NY State of Mind.† It’s filled with metaphors and similes along with a beat that gives a backbone to the track. â€Å"Illmatic,† without a doubt, is one the greatest hip-hop albums of all time. Nas’s style is considered East Coast rap since he hails from New York. His lyrics are  ­influenced by his life experiences, and each track tells a story. We will write a custom essay sample on Nas – â€Å"Illmatic† or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page â€Å"Illmatic† displays Nas’s struggles, high points, and all the in-betweens. â€Å"Illmatic† was released in 1994. Nas’s album is astonishing for an artist’s debut. For 14 years, he hasn’t managed to top it. Neither has any other emcee. Not to mention, the New York native was just 19 when this  ­album was  ­released. This album is unquestionably a classic that every hip-hop fan should have. Honestly, there are no downfalls in this album. Everything about it is as close to perfect as you can get. I would rate it a 9.9. The only reason it doesn’t get a 10 is I believe nothing in the world is perfect.

3 Types of Problems with Complex Phrasal Adjectives

3 Types of Problems with Complex Phrasal Adjectives 3 Types of Problems with Complex Phrasal Adjectives 3 Types of Problems with Complex Phrasal Adjectives By Mark Nichol In each of the following sentences, an error pertaining to hyphenation results in a faulty phrasal adjective. Discussion and revision explain and demonstrate how to solve the problem. 1. The company appeared to violate federal law by offering high-interest rate loans in states where such loans are prohibited. This sentence describes rate loans of a high-interest nature, but that’s not the intent of the statement. The phrase â€Å"high interest rate† serves as a phrasal adjective describing the type of loans in question, so those three words should be hyphenated together: â€Å"The company appeared to violate federal law by offering high-interest-rate loans in states where such loans are prohibited.† Alternatively, the sentence can be relaxed: â€Å"The company appeared to violate federal law by offering loans at high interest rates in states where such loans are prohibited.† (Note that no hyphenation occurs in â€Å"high interest rates† because here, high and interest do not modify rates; rather, high modifies â€Å"interest rates.† 2. A robust â€Å"think outside the box† process is needed to establish and sustain this vital dialogue between management and the board. The writer has enclosed â€Å"think outside the box† in scare quotes, apparently on the assumption that the phrase is an obscure idiom that needs to be emphasized as such, but it is familiar to the point of clichà © and therefore doesn’t merit any special treatment. But in this sentence, it is a phrasal adjective, so the four words should be linked with hyphens: â€Å"A robust think-outside-the-box process is needed to establish and sustain this vital dialogue between management and the board.† (If scare quotes were merited, the marks would serve to visually unify the phrasal adjective, so hyphenation would be redundant.) 3. Production environment access management controls can often be improved by providing user access based on role and title. It is technically correct to hyphenate the noun-cum-adjective stack that begins this sentence, but such a laboriously extended phrasal adjective is clumsy. Simplify such a construction by altering the syntax with insertion of prepositions, as in the first example above: â€Å"Controls for access management in the production environment can often be improved by providing user access based on role and title.† Want to improve your English in five minutes a day? Get a subscription and start receiving our writing tips and exercises daily! Keep learning! Browse the Grammar category, check our popular posts, or choose a related post below:Cost-Effective vs. Cost-EfficientBody Parts as Tools of MeasurementMay Have vs. Might Have

Free Essays on Parnoid

..p.html..p.html Diagnostic Criteria A. A pervasive distrust and suspiciousness of others such that their motives are interpreted as malevolent, beginning by early adulthood and present in a variety of contexts, as indicated by four (or more) of the following: 1. suspects, without sufficient basis, that others are exploiting, harming, or deceiving him or her 2. is preoccupied with unjustified doubts about the loyalty or trustworthiness of friends or associates 3. is reluctant to confide in others because of unwarranted fear that the information will be used maliciously against him or her 4. reads hidden demeaning or threatening meanings into benign remarks or events 5. persistently bears grudges, i.e., is unforgiving of insults, injuries, or slights 6. perceives attacks on his or her character or reputation that are not apparent to others and is quick to react angrily or to counterattack 7. has recurrent suspicions, without justification, regarding fidelity of spouse or sexual partner B. Does not occur exclusively during the course of Schizophrenia, a Mood Disorder With Psychotic Features, or another Psychotic Disorder and is not due to the direct physiological effects of a general medical condition. Note: If criteria are met prior to the onset of Schizophrenia, add "Premorbid," e.g., "Paranoid Personality Disorder (Premorbid)." Associated Features Odd/Eccentric/Suspicious Personality Dramatic/Erratic/Antisocial Personality Differential Diagnosis Delusional Disorder, Persecutory Type; Schizophrenia, Paranoid Type; Mood Disorder With Psychotic Features; Personality Change Due to a General Medical Condition; symptoms that may develop in association with chronic substance use; paranoid traits associated with the development of physical handicaps; Schizotypal Personality Disorder; Schizoid Personality Disorder; Borderline and Histrionic Personality Disorders; Avoidant Personality Disorder; ... Free Essays on Parnoid Free Essays on Parnoid ..p.html..p.html Diagnostic Criteria A. A pervasive distrust and suspiciousness of others such that their motives are interpreted as malevolent, beginning by early adulthood and present in a variety of contexts, as indicated by four (or more) of the following: 1. suspects, without sufficient basis, that others are exploiting, harming, or deceiving him or her 2. is preoccupied with unjustified doubts about the loyalty or trustworthiness of friends or associates 3. is reluctant to confide in others because of unwarranted fear that the information will be used maliciously against him or her 4. reads hidden demeaning or threatening meanings into benign remarks or events 5. persistently bears grudges, i.e., is unforgiving of insults, injuries, or slights 6. perceives attacks on his or her character or reputation that are not apparent to others and is quick to react angrily or to counterattack 7. has recurrent suspicions, without justification, regarding fidelity of spouse or sexual partner B. Does not occur exclusively during the course of Schizophrenia, a Mood Disorder With Psychotic Features, or another Psychotic Disorder and is not due to the direct physiological effects of a general medical condition. Note: If criteria are met prior to the onset of Schizophrenia, add "Premorbid," e.g., "Paranoid Personality Disorder (Premorbid)." Associated Features Odd/Eccentric/Suspicious Personality Dramatic/Erratic/Antisocial Personality Differential Diagnosis Delusional Disorder, Persecutory Type; Schizophrenia, Paranoid Type; Mood Disorder With Psychotic Features; Personality Change Due to a General Medical Condition; symptoms that may develop in association with chronic substance use; paranoid traits associated with the development of physical handicaps; Schizotypal Personality Disorder; Schizoid Personality Disorder; Borderline and Histrionic Personality Disorders; Avoidant Personality Disorder; ...

Moral Problem Essay Example | Topics and Well Written Essays - 500 words

Moral Problem - Essay Example This occurs when an organization has control over a large part of the market when compared to its main competitors (34). In most cases, the companies are normally given leeway to operate at the same level and in the same environment with other smaller companies. This is normally controversial because the smaller companies are expected to compete for the same customers as the bigger companies, even if they (the smaller companies) may sometimes have fewer resources. The matter is not helped by the fact that most governments do not have any legal frameworks to act as guides to what extent big multinationals can compete with smaller local companies (Koggel 47). Wal-Mart is inarguably the world’s largest retail store with operational branches in more than half of the world’s main cities. Due to its size and resources, the mega-store chain can afford to offer consumer products at relatively cheap prices as compared to other similar stores. This is normally a great problem to the smaller home grown retail stores which have to make profit and remain competitive at the same time. If they were to offer their products at the prices offered at Wal-Mart, many of them would incur great loses and would have to close business if they continued doing so.

Social Work Practice- Alcohol Misuse in Young People of Ages of 16-19 Essay

Social Work Practice- Alcohol Misuse in Young People of Ages of 16-19 Years - Essay Example Psychological theories play a very important role in the social work practice on alcohol abuse among the young people. According to the Social Learning theory by Albert Bandura, people are not born with specific types of behavior (Monti, 2002; pp. 3-6). This is to mean that people learn behaviors from different contexts such as the environment in which the individuals live in. The theorist continues to indicate that the response patterns that individuals acquire are either acquire through direct experience or through observation of concepts they see in their environment (Monti, 2002; pp. 3-6). On the grounds of this theory, it is validated to indicate that the environment is the major source of learning and the main source of observable behavior. In the context of the young adults aged 16-19 years, the theory explains that they learn new behaviors through modeling. Additionally, Bandura argues that the social behaviors are learned through watching as well as performing the actions learned. For instance, a young teenager who sees his/her peers using alcohol as a form of recreation, they are likely to learn this behavior and even adopt the same as part of their lifestyle (Monti, 2002; pp. 3-6). Despite numerous criticisms that the social learning theory simply takes the individuals as mere unreceptive recipients of the stimuli in the environment as Bingham & Conner argue (2010; pp.10), this theory is relevant in the study of alcohol misuse, as the misuse of alcohol can be termed as a social practice as the misusers of the alcohol simply learn the habit as a result of mere interactions with the various actors in the environment. The biopsychosocial model of addiction explains that alcohol misuse has a link with the psychological and social factors  (Miller, 2011; pp.12). Biologically, individuals may have the genetic inheritance of alcohol syndrome while psychosocially, the environment may influence an individual to alcohol misuse.  

Human Error and Perceptual Control Theory

Human Error and Perceptual Control Theory Overview In this paper, I will explore and advocate the importance of both Human Error and Perceptual Control Theory for design of complex human-machine systems, enhanced user experience and better human performance and safety. Human Error Errors are the result of actions that fail to generate the intended outcomes (SKYbrary). Human operators are one of the biggest sources of errors in any complex system (Shelton, 1999). According to Sanders McCormick (1976), Human error is an inappropriate or undesirable human decision or behavior that reduces, or has the potential for reducing effectiveness, safety and performance of a system and/or human (Kurniawan). Error Types Researchers have differentiated between two types of error:1) slipsand lapses 2) mistakes. Slips and lapses According to SKYbrary, a person intends to carry out an action, the action is appropriate, carries it out incorrectly, and the desired goal is not achieved an execution failure has occurred. Execution errors result from failures in the execution and/or storage stage of an action sequence. Slips relate to observable actions and are commonly associated with attentiveness or perceptual failures. Lapses are more internal events and generally involve failures of memory (SKYbrary). Mistakes As mentioned in UKEssays.com, Mistakes occur when an intended outcome is not achieved even though there was adherence to the steps in the plan. This is usually a case in which the original plan was wrong, was followed, and resulted in an unintended outcome (UKEssays.com). Error mechanisms The following three error mechanisms are widely accepted, which correlate with human performance levels. Skill-based errors Errors of execution Occur during highly routine activities or automated tasks with occasional checks Action chosen by the operator but not in accordance with the operator’s intentions Done by highly experienced individuals due to inattention or distraction Rule-based errors Applies to familiar situations Incorrect application of a good rule, correct application of a bad rule or failure to apply a good rule Knowledge-based errors Occur in unique and unfamiliar situations Result from inadequate analysis or decision making (trial and error) Done by operators with insufficient knowledge Applications of Human error theory Human error is inevitable. However, human error mitigation strategies could be devised by understanding various error mechanisms and triggers, as depicted in the human error theory. Superior system design, better recruitment and selection of operators, training, stress and fatigue prevention measures, better equipment procedures and improved work environment can reduce error consequences and likelihood. By understanding human error, system designers can plan for likely error scenarios, and implement barriers to prevent or mitigate the occurrence of potential errors. Some approaches to build a better human machine interaction system are explained below. Identification of error environment First step in human error mitigation approach is to understand the work environment, recognize capacity of the users, identify possible loopholes n the system and be familiar with potential user error occurrence and consequences. Likelihood of an error and severity of potential harm should also be examined. For example, FDA (Food and Drug Administration) requires manufacturers to submit a failure analysis report FMEA (Failure Mode and Effect Analysis) while launching any new medical device. Design solutions to address errors Error elimination First and foremost design strategy is to eliminate design features, which are sources of user errors. Design weaknesses identified during observation and task analysis should be removed or revised. Removal of excessive and irrelevant information, inclusion of validity checks and task automations are some design aspects that support error elimination approach. Additionally, carrying out periodical test runs of the system might be helpful in eliminating some of the rules based errors. Error reduction Designers should try to reduce error occurrences for features that cannot be removed completely. Building consistent designs and providing alerts, warnings, confirmations and other necessary feedback to users may prevent users to make errors of execution (skill-based errors). Consequence elimination Consequence elimination is an approach to prevent potential harm after the occurrence of error. Designers can devise features that provide information about potential harm and ways to correct the situation (e.g. undo) and/or prevent onset of side effects (e.g. automatic locking or shutdown, process delays) in order to prevent error consequences. Consequence reduction This is a last design alternative a designer can look into if above mentioned options are not feasible to incorporate. Decreasing the effect of error is helpful especially in catastrophic situations. Design of supplementary features is usually necessary to achieve this purpose. Backup and restore features, automatic reporting to stakeholders/police/medical teams and automated substitute drug delivery are some of the techniques for reducing effects of consequences. Error elimination and error reduction are often the most cost effective methods to avert user errors. Trainings Knowledge-based errors can be eliminated to some extent by providing system-oriented trainings, especially to novice users. On the other hand, a different training program could be devised for experienced users. Periodical trainings could keep experts up-to-date with latest developments in their field and assess their knowledge of system procedural checks. Essentially, this may help minimizing skill-based errors. Perceptual Control Theory (PCT) Perceptual control theory (PCT) is a theory of human and animal behavior. It is based on the principles of control theory (Powers, 1973). As cited by Lulham (2005), at the core of PCT is the idea that many of the processes involved in how human functions are most appropriately conceptualized and modelled as dynamic control processes (Powers, 1999b). Control processes are proposed to be fundamental to many functions including those related to physiological (e.g. temperature regulation), neural (e.g. attention), motor control (e.g. driving a car), psychological (e.g. maintenance of a criminal identity) and social (e.g. staff-detainee relationship) functions (Lulham, 2005). According to Cherry Farrel (1998), PCT exploits the concept of a purpose behind the behaviour. A perception (which is a transformation of stimuli from the world) is then compared to its reference signal, and a perceptual error is generated. A person acts on the world in such a manner to minimise this error. The stabilisation of this control loop is the essence of PCT (Chery Farrell , 1998). Applications of PCT Using perceptions for building complex systems System environments are becoming increasingly complex. Traditional cause and effect methods of understanding system operations and user interactions may not work well in order to employ personalization and user experience in these complex systems. According to pctweb.org, the person compares a ‘standard’ (what they want) with what they are experiencing right now (their perception). The difference between the two – the discrepancy or error is being measured. The bigger the error the more the effort the person makes to reduce it, until the error is zero – this means they get what they want (pctweb.org). The basic premise of PCT is that human behavior is not about the behavior itself, but about reinforcing desired perception (O’Neal, 2012). Understanding and applying this concept of individually preferred perceptions through PCT will help in designing effective personal information management for complex systems and enhancing the overall user experience. User research and analysis PCT is particularly helpful in understanding users’ behaviors and motives behind their actions. Often system designers evaluate possible system states and static change in control values needed to achieve those states. Tasks are carried out on the controls to attain the new state and user is though of as a controller of these tasks. Designers use task analysis method to perform user research and concentrate on physical tasks a user performs. However, instead of system oriented or designer oriented view, PCT goes much deeper and offers user’s standpoint. PCT provides framework to realize dynamic nature of user interactions. System designers can use PCT to understand how users constantly perceive and compare system states and take dissimilar actions to reinstate appropriate system state every time. Furthermore, Powers (1973) proposed behavior as a control of perceptions. Instead of focusing on a physical activity during the task analysis, PCT suggests focusing on users’ behaviors that lead them to perform actions to achieve desired perception (system state). Thus, using the PCT framework, designers can integrate physical, cognitive and behavioral sides of a user’s interaction with the system. Moreover, PCT analysis of intentions from different user groups exposes their shared narrative, which in turn, helps in finding system requirements for hidden, absent user (O’Neal, 2012). For example, a customer service representative might use call center software while working to resolve an issue with a customer. While the customer is not a direct user of the software system, he is affected indirectly. The customer here is a hidden user. His perceptions should be analyzed to understand his requirements and objectives while developing the call center system. Empowered designs PCT offers a design framework toward the satisfaction of the users desired percepts. Human-machine system performance is enhanced when the displays and controls are designed to allow the operator to perceive and transmit information in order to minimize the perceptual error (Chery Farrell , 1998). According to PCT, when a user interacts with the system, he is constantly trying to bring equilibrium, changing his perception to the reference point, which is his new perception. Keeping this in mind, a designer should build the system that transforms from an old state to the new state seamlessly, provides estimate of gap between old and new state, furnish necessary feedback to keep the user aware of the environment variables and helps the user to manage disturbances. These functionalities will help users to gain accurate information regarding their perceptions, empower them to undertake correct amount of action to reach to new perception, ultimately helping them achieve self-regulation and stability. For example, the windshield of the car let the user scan his environment and gather information necessary to their perception, the car dashboard continuously displays speed and other important elements to help user assess different system states, and the gear stick helps user achieve n ew state from the old one smoothly. Other features like wiper, headlights, turn signals etc. facilitate users to manage disturbances as much as possible. Thus, human-machine designs should be compatible with user’s interpretations of information in order to improve their decision making process and overall system performance. Conclusion Both human error and PCT frameworks are valuable in building complex system designs to facilitate information management, enhance security and improve both system and human performance. By understanding fundamentals of human errors, designers can build a system that is more usable, provides meaningful feedbacks and include training, procedural checks and incentive programs. However, according to Shelton (1999), there is a trade-off between making the HCI relatively easy and intuitive and ensuring that system safety is not compromised by lulling the operator into a state of complacency. In PCT, the error is continuously measured to achieve equilibrium. Per Lulham (2005), those involved in developing the theory believe PCT has significant potential to change the way human functioning is understood. However, further research is required for advancement of PCT framework. References Component-based usability testing. (n.d.). Retrieved from Wikipedia: http://en.wikipedia.org/wiki/Component-Based_Usability_Testing Embrey, D. Understanding Human Behaviour and Error. Human Reliability Associates. Latino, R. J. (2007, Nov). Defining and reducing human error. Briefings Page on Patient Safety . O’Neal, A. (2012, July). Intention-Focused Design: Applying Perceptual Control Theory to Discover User Intent. Retrieved 2013, from UXmatters.com: http://www.uxmatters.com/mt/archives/2012/07/intention-focused-design-applying-perceptual-control-theory-to-discover-user-intent.php PCTweb. (n.d.). What is PCT? Retrieved from PCTweb: http://www.pctweb.org/whatis/whatispct_03.html Powers, W. T. (n.d.). A brief introduction to Perceptual Control Theory . Retrieved from Frontier: http://www.frontier.net/~powers_w/whatpct.html Shelton, C. P. Human Interface/Human Error. Carnegie Mellon University. SKYbrary. (n.d.). Human Error Types. Retrieved from SKYbrary: http://www.skybrary.aero/index.php/Human_Error_Types 1 Lajja Mehta