decision support systems Flashcards
what is a decision support system ? what does a DSS do
a decision support system (DSS) is designed to help managers make decisions that will further their organisations goal.
- Assist users to make a choice between two or more alternatives by providing information, models and analysis tools
- a DSS allows users to manipulate data directly, to incorporate data from external sources and to create data models of ‘what if’ scenarios
- a DSS provides the support required so that correct decisions can be made. for example, a DSS could show trends in product sales over a three-year period so that material supplies and stock levels can be adequately maintained.
- Supply evidence to assist decision makers determine alternatives and then prioritise one alternative over other possible alternatives
what are structured situations
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- decisions are automated
- decision support systems are not required
what are semi-structured situations
- there is a method to follow
- requirements are clear cut
They follow a method to reach a decision, but the correct decision is not guaranteed. in these situations, the procedure for arriving at a solution is usually known; however, it might involve a degree of subjective judgement. there is some indication of the path to take but some of the information related to the problem may not be available, might lack precision or be uncertain. eg A bank officer deciding how much to lend to a customer. decisions involve some degree of uncertainty. most real-world situations are semi-structured and can use a DSS
what are unstructured situations
- there is no method to reach the decision
- judgements are required
- requires insights into the problem
this requires human intuition as a basis for finding a solution. there is no clear-cut path to the decision. information relevant to the solution might be missing, and few farts of the solution can be tackled using concrete models. No structured method for reaching a decision, too many variables, many are unknown and their interactions are highly complex and poorly understood. eg predicting stock prices
what are some examples of semi-structured situations
- a bank officer deciding how much to lend to a customer
- fingerprint matching
how does decision making in a bank office (deciding how much to lend to a customer) work
they assess the risk involved in lending the money and make a decision on the most suitable loan
- The customer’s income is sufficient to meet the regular repayments
- The customer’s income will continue at current levels for the term of the loan
- The bank will be able to recover their funds if the customer is unable to meet their repayment obligations
how does decision making in fingerprint matching work
- Automated fingerprint identification system used to help fingerprint experts match prints
- It generates a list of possible matchers , but an expert is still sometimes required to make a decision and use judgement regarding the degree of similarity between the 2 prints
what are some examples of unstructured situations
- predicting stock prices
- disaster relief management
- weather forecasting
how does decision making in predicting stock prices work
- Info. on share prices is stored in a spreadsheet or database used to predict future stock prices
- Unforeseen events occur which affect decisions made, therefore decisions cannot be guaranteed
- Data inputs to stock market prediction decision support systems include:
- Past sale prices and quantity of shares traded for each public company’s shares
- Data specific to individual companies
- Industry specific data
- Overall historical measures of stock market performance
- Advice and predictions from politicians and stock market expert
how does disaster relief management work
- Disasters unexpected and thus relief organisations generally respond after disaster has occurred
- Decision making in these situations determine the effectiveness of the response to the disaster
- DSS’s can
- Store data describing the details of the disaster
- Actions required to relieve the situation and resources available to perform these actions
what are some systems used to support decision making
- spreadsheets
- databases
- expert systems
- neural networks
- data warehouses
- group decision support systems
- geographic information systems (GIS)
- management information systems (MIS)
what are spreadsheets and what do they do
- Organises data into one or more worksheets within a grid of columns and rows
- Valuable for performing “what-if” analysis to alter inputs and view the effect on the outputs
what are some advantages of electronic spreadsheets
- calculation is quick and accurate using a large range of in-built functions
- data is easily formatted and presented in a variety of outputs including charts or graphs
- data can be copied within a spreadsheet or integrated into other spreadsheets or application programs
- storage of data is faster and takes up less space
- retrieval of data is fast and efficient
- the spreadsheet can be used as a calculating tool in a large number of diverse situations
why do businesses use spreadsheets
- perform cost-structure analysis
- prepare break-even analysis
- produce reports
- show and forecast trends
- prepare and store budgets
- compile profit and loss statements
- produce and store invoices
- perform ‘what-if’ trials (such as changing prices or profit levels)
why do scientists use spreadsheets
- compile statistical research
- produce graph results
- test and simulate a range of variable conditions
- build scientific models of data
- perform ‘what if’ trials
what are the 3 types of data that may be entered into a cell in a spreadsheet (expand, what are they)
- labels - labels are non-numeric data. labels may be used as a spreadsheet title, column or row headings or any other words or text used to identify or clarify spreadsheet data. labels cannot be used in calculations
- values - values are numeric data that are used in calculations. it is possible to change the format of a value so that the data can be displayed in dollar, per cent, scientific or data forms.
- formulas - formulas carry out calculations using values in other cells. the formula itself is usually not displayed, only the value calculated is shown
what is absolute and relative referencing in formulas
formulas - formulas carry out calculations using values in other cells. the formula itself is usually not displayed, only the value calculated is shown
- relative cell reference means that a cell reference in a formula is relative to its position. if the formula is copied or moved to another location in the spreadsheet the formula will change relative to its new position
- absolute cell referencing means a cell reference in a formula is fixed and will not change when it is copied or moved. absolute cell reference is indicated by a $ preceding the cell reference, for example $A$3
how do databases help decision making
- They enable users to access large amounts of data to make a decision.
- Retrieving data to make a decision usually requires the use of a query (QBE / SQL).
what is a data warehouse
Data warehouse is a database that collects information from different data sources. It is a storage area of raw data that can be analysed to assist organisations to make decisions.