Activity Network Diagram Method

A five level pyramid model of different types of Information Systems based on the information processing requirement of different levels in the organization. The first level represents transaction processing systems to process basic data. The second level represents office support systems to process information in office. The third level represents management information systems to process information by managers. The fourth level represents decision support systems to process explicit knowledge. The fifth level represents executive information systems to process tacit knowledge.
"A Computer(-Based) Information System is essentially an IS using computer technology to carry out some or all of its planned tasks. The basic components of computer based information system are:
(1) Hardware - these are the devices like the monitor, processor, printer and keyboard, all of which work together to accept, process, show data and information.
(2) Software - are the programs that allow the hardware to process the data.
(3) Databases - are the gathering of associated files or tables containing related data.
(4) Networks - are a connecting system that allows diverse computers to distribute resources.
(5) Procedures - are the commands for combining the components above to process information and produce the preferred output.
The first four components (hardware, software, database and network) make up what is known as the information technology platform. Information technology workers could then use these components to create information systems that watch over safety measures, risk and the management of data. These actions are known as information technology services." [Information systems. Wikipedia]
This pyramid diagram was redesigned using the ConceptDraw PRO diagramming and vector drawing software from Wikimedia Commons file Five-Level-Pyramid-model.png. [commons.wikimedia.org/ wiki/ File:Five-Level-Pyramid-model.png]
This file is licensed under the Creative Commons Attribution 3.0 Unported license. [creativecommons.org/ licenses/ by/ 3.0/ deed.en]
The triangle chart example "Information systems types" is included in the Pyramid Diagrams solution from the Marketing area of ConceptDraw Solution Park.

A four level pyramid model of different types of Information Systems based on the different levels of hierarchy in an organization. The first level represents transaction processing systems for workers. The second level represents management information systems for middle managers. The third level represents decision support systems for senior menegers. The fourth level represents executive information systems for executives.
"The "classic" view of Information systems found in the textbooks in the 1980s was of a pyramid of systems that reflected the hierarchy of the organization, usually transaction processing systems at the bottom of the pyramid, followed by management information systems, decision support systems, and ending with executive information systems at the top. Although the pyramid model remains useful, since it was first formulated a number of new technologies have been developed and new categories of information systems have emerged, some of which no longer fit easily into the original pyramid model.
Some examples of such systems are:
data warehouses,
enterprise resource planning,
enterprise systems,
expert systems,
search engines,
geographic information system,
global information system,
office automation." [Information systems. Wikipedia]
This diagram was redesigned using the ConceptDraw PRO diagramming and vector drawing software from Wikimedia Commons file Four-Level-Pyramid-model.png. [commons.wikimedia.org/ wiki/ File:Four-Level-Pyramid-model.png]
This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license. [creativecommons.org/ licenses/ by-sa/ 3.0/ deed.en]
The triangle chart example "Information systems types" is included in the Pyramid Diagrams solution from the Marketing area of ConceptDraw Solution Park.

The FTA diagram sample "Fault tree analysis - Insulin delivery system" was redesigned from the illustration of "CMSI 641: Introduction to Software Engineering. Design of Critical Systems. B.J. Johnson. 2005. Loyola Marymount University".
"Another way of assessing hazards is using fault tree analysis. In this process, each of the identified hazards is covered by a detailed analysis to find out what might cause it. Either inductive or deductive reasoning is applied. In the case of software hazards, the usual focus is to determine faults that will cause the system to fail to deliver a system service, such as a monitoring system. A "fault tree" is constructed to link all the possible situations together, to help identify the interrelationships of the failures, which modules may cause them, and what "trickle-down effects" there might be. Here is an example of a fault tree, as applied to the Insulin delivery system from Sommerville...
Note that this tree is only partially complete, since only the potential software faults are shown on the diagram. The potential failures involving hardware, such as low battery, blood monitor or sensor failure, patient over-exertion or inattention, or medical staff failure are noticeable by their absence.
The fault tree and safety specification processes are two ways of helping with system risk assessment tasks. Once the risks are identified, there are other assessments that need to take place. First, the likelihood of the risk occurrance must be assessed. This is often quantifiable, so numbers may be assigned based on things like MTBF, latency effects, and other known entities. There may be other non-quantifiable contributors to the risk likelihood, however, such that these must be assessed and estimated by experts in the domain. (Don't short-change this process when dealing with critical systems!) Finally, the risk assessment must include the severity of the risk, meaning an estimation of the cost to the project in the event the risk item actually does occur. "Cost to the project" means all associated costs, including schedule delays, human injury, damage to hardware, corruption of data, and so on."
[myweb.lmu.edu/ bjohnson/ cmsi641web/ week15-2.html]
The FTA diagram example "Fault tree analysis - Insulin delivery system" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Fault Tree Analysis Diagrams solution from the Engineering area of ConceptDraw Solution Park.