SYSTEMS ANALYSIS & DESIGN PHASE 3 SYSTEMS DESIGN Output Design

SDLC Phases Phase 3: Systems Design

SDLC Phases Phase 3: Systems Design Objectives Review general design requirements Complete output design, input design, file and database design, and system architecture

Chapter 6 Output Design

Objectives Explain the differences between logical and physical design Discuss the objectives of systems design and provide guidelines for good design List and describe the major activities of the systems design phase Design and use appropriate codes in systems design and development

Objectives Provide examples of types of output, including new technology-based methods of information delivery Describe the classifications of output reports and explain the differences among them Design effective printed reports that will meet user requirements

Objectives Design screen reports that are easy to understand and use Explain output control concepts and methods

Introduction Output design is the first of four chapters covering the systems design phase of the SDLC Chapter topics Overview of systems design Specific tasks in output design Output control and automated design tools

Systems Design Overview Logical design defines necessary system requirements and called an essential model Logical design specifies what must take place, not how it will be accomplished Physical design concerns how the system will be implemented Physical design describes specific components and system specifications

Systems Design Overview The relationship between analysis and design Logical and physical design are related closely Analysis should be completed before design Developers do not return from design to analysis work except in limited circumstances An important fact is overlooked Users have significant new needs Legal/governmental requirements change Unforeseen design issues or problems arise

Systems Design Overview Systems design activities All system components are related closely Must understand the entire logical design Click to see Figure 6-1

Systems Design Overview Systems design steps Review the system requirements Design the system Output Input Files and databases System architecture Present the systems design Click to see Figure 6-2

General Guidelines for Systems Design Characteristics of a well-designed system Effective Satisfies defined requirements Accepted by users Reliable Adequately handles errors (input, processing, hardware, or human mistakes) Maintainable Well-designed and flexible Future modifications considered

General Guidelines for Systems Design Design suggestions Three categories of considerations User considerations Data considerations Processing considerations Click to see Figure 6-3

General Guidelines for Systems Design User considerations Make the system user-friendly Consider where users receive output, or provide input to the system Anticipate future needs Users Information system Organization

General Guidelines for Systems Design Data considerations Enter data where and when it occurs Verify data where it is input Use automated data-entry methods Control access for data entry Report all entries or changes to critical values Enter data into a system only once Avoid data duplication Click to see Figure 6-4

General Guidelines for Systems Design Processing considerations Use a modular (structured) design Design modules that perform a single function

TRADEOFF Good design: the flexibility issue Hardcoded (fixed) values are inflexible Users’ needs constantly change Variable parameters can provide flexibility Default values can be combined with user-defined parameters

A KEY QUESTION What if users could design most of their own reports without IS assistance? Would they request as many reports or the same types of reports? What are the pros and cons of giving users total control over output?

General Guidelines for Systems Design Design tradeoffs Design goals often conflict with each other Easier use might create more complex programming requirements More flexibility might increase maintenance needed Meeting one user’s requirements might make it harder to satisfy another’s needs A major issue is quality versus cost

Designing and Using Codes A code is a set of letters or numbers that represents an item of data Codes serve many useful purposes Save storage space and costs Reduce data transmission time Decrease data entry time Can reveal or conceal information Can reduce input errors Click to see Figure 6-5

Designing and Using Codes Types of coding Sequence codes Block sequence codes Classification codes Alphabetic codes Mnemonic codes Click to see Figure 6-6

Designing and Using Codes Types of Coding Sequence codes Block sequence codes Classification codes Alphabetic codes Mnemonic codes Significant digit codes Click to see Figure 6-7

Designing and Using Codes Types of coding Sequence codes Block sequence codes Classification codes Alphabetic codes Mnemonic codes Significant digit codes Derivation codes Click to see Figure 6-8

Designing and Using Codes Types of coding Sequence codes Block sequence codes Classification codes Alphabetic codes Mnemonic codes Significant digit codes Derivation codes Cipher codes Action codes Self-checking codes Click to see Figure 6-9

Designing and Using Codes Developing a code Keep codes concise Allow for expansion Keep codes stable Makes codes unique Use sortable codes Avoid confusing codes Make codes meaningful Use a code for a single purpose Keep codes consistent

Introduction to Output Design Users judge a system based on how well the output helps them perform their jobs Output must be Useful Accurate Understandable Timely

Introduction to Output Design Checklist for output design Design process depends on What is the purpose of the output? Who or what wants this information, why is it needed, and how will it be used? What information will be included? What format should be used? When will information be provided, and how often must it be updated? Will simultaneous user access be required? Are security or confidentiality issues involved that need to be considered?

Types of Output and Information Delivery Technology affects how people communicate and obtain information Printers Screens Plotters Audio output E-mail Links to Web pages Automated facsimile system Computer output microfilm (COM) Other specialized devices Click to see Figure 6-10

Types of Output and Information Delivery Printed output Impact printers Laser printers Turnaround documents Advantages/disadvantages of printed output Many people prefer to work with paper Paper is portable Printed output is expensive to purchase, print, store, and dispose of Printed output is outdated quickly

Types of Output and Information Delivery Screen output The screen is the most familiar output device Monitor CRT (cathode ray tube) LCD (liquid crystal display) VDT (video display terminal) Graphical output allows various special effects and user-friendly features Screen output reflects immediate data changes

Types of Output and Information Delivery Other types of information delivery Audio output Click to see Figure 6-11

Types of Output and Information Delivery Other types of information delivery Audio output Automated facsimile and faxback systems E-mail Links to Web pages Specialized forms of output Click to see Figure 6-12

Designing Printed Reports Reports can be classified by content Detail reports Exception reports Summary reports Reports also can be classified by distribution Internal reports External reports

Designing Printed Reports Detail reports Provide the most information At least one line of output is produced for each record processed Detail reports can be quite lengthy Click to see Figure 6-13

Designing Printed Reports Detail reports Provide the most information At least one line of output is produced for each record processed Detail reports can be quite lengthy Control-break reports Use a control field Must be sorted on the control field before printing A control break occurs when the control field value changes Click to see Figure 6-14

Designing Printed Reports Exception reports Show only records that meet a specific condition Useful when particular information is required Special parameter queries can be used to select only the records that meet specified conditions Click to see Figure 6-15

Designing Printed Reports Summary reports Show only subtotals and totals Useful for upper-level managers who do not require extensive detail Click to see Figure 6-16

Designing Printed Reports Internal reports Distributed within the organization Usually printed on stock paper Blank, single ply, standard size Less expensive Can be used for many types of reports

Designing Printed Reports External reports Distributed outside the organization Might include statements, invoices, or paychecks Usually printed on special forms More expensive than stock paper Paper must be changed for each report printing job Multi-part forms must be separated or decollated Click to see Figure 6-17

Designing Printed Reports External reports Distributed outside the organization Might include statements, invoices, or paychecks Usually printed on special forms More expensive than stock paper Paper must be changed for each report printing job Multi-part forms must be separated or decollated Special forms can use preprinted graphics and logos Click to see Figure 6-18

Designing Printed Reports Usually printed on special forms More expensive than stock paper Paper must be changed for each report printing job Multi-part forms must be separated or decollated Special forms can use preprinted graphics and logos Special applications, such as checks, require special forms Click to see Figure 6-19

Designing Printed Reports Designing the report Most reports use graphical design Choice of typefaces and scalable fonts More design flexibility Some reports are character-based Printed on high-speed impact printers Require printer spacing charts for layout and design Click to see Figure 6-20 Click to see Figure 6-21

Designing Printed Reports Stock paper reports Page heading lines Column heading lines Column heading alignment (as shown in Figure 6-22) Click to see Figure 6-22

Designing Printed Reports Stock paper reports Page heading lines Column heading lines Column heading alignment (as shown in Figure 6-22) Spacing between columns Order of data items on detail lines Click to see Figure 6-28

Designing Printed Reports Stock paper reports Page heading lines Column heading lines Column heading alignment (as shown in Figure 6-22) Spacing between columns Order of data items on detail lines Grouping detail lines Click to see Figure 6-29

Designing Printed Reports Stock paper reports Page heading lines Column heading lines Column heading alignment (as shown in Figure 6-22) Spacing between columns Order of data items on detail lines Grouping detail lines Report footing Improving a report design Documenting a report design Click to see Figure 6-30

Designing Printed Reports Stock paper reports Page heading lines Column heading lines Column heading alignment (as shown in Figure 6-22) Spacing between columns Order of data items on detail lines Grouping detail lines Report footing Improving a report design Documenting a report design Design consistency Click to see Figure 6-31

TRADEOFF What can you do when there are not enough print positions on the page? Several possible options Abbreviate the column headings, with legend below Print subtotals and totals (as shown in Figure 6-23) Click to see Figure 6-23

TRADEOFF What can you do when there are not enough print positions on the page? Several possible options Abbreviate the column headings, with legend below Print subtotals and totals (as shown in Figure 6-23) Alternate odd/even months (as shown in Figure 6-24) Click to see Figure 6-24

TRADEOFF What can you do when there are not enough print positions on the page? Several possible options Abbreviate the column headings, with legend below Print subtotals and totals (as shown in Figure 6-23) Alternate odd/even months (as shown in Figure 6-24) Split the report into versions (as shown in Figure 6-25) Click to see Figure 6-25

TRADEOFF What can you do when there are not enough print positions on the page? Several possible options Abbreviate the column headings, with legend below Print subtotals and totals (as shown in Figure 6-23) Alternate odd/even months (as shown in Figure 6-24) Split the report into versions (as shown in Figure 6-25) Use stacked headings (as shown in Figure 6-26) Click to see Figure 6-26

TRADEOFF Several possible options Abbreviate the column headings, with legend below Print subtotals and totals (as shown in Figure 6-23) Alternate odd/even months (as shown in Figure 6-24) Split the report into versions (as shown in Figure 6-25) Use stacked headings (as shown in Figure 6-26) Use two detail lines (as shown in Figure 6-27) Click to see Figure 6-27

A KEY QUESTION The problem: users receive many reports, but do not seem to read them The solution: a procedure that requires users to review and justify their information needs The key question: Jan Lauten needs to recommend a procedure to her boss, Lynn Jennings. What advice can you give to Jan?

Designing Printed Reports Special form reports Can use printer spacing charts to design Placement of preprinted graphics can be indicated Functional and aesthetic design principles are important Field labels should be short but descriptive Avoid nonstandard abbreviations Order and placement of printed fields should be logical Totals should be identified clearly Click to see Figure 6-32

Designing Printed Reports Report volume and time calculations Accurate estimates are necessary to Determine whether printing capacity is adequate Achieve efficient printing operations Ensure timely delivery of finished reports Provide reliable forecasts of paper and storage needs

Designing Printed Reports Report volume and time calculations Factors to consider Types of printers Print volume calculations Print-time calculations Click to see Figure 6-33 Click to see Figure 6-34 Click to see Figure 6-35

Designing Screen Output Major advantage is timeliness Screen output can be produced when and where needed

Designing Screen Output Screen design considerations Many print design principles apply to screens Screens also need instructions and messages Users require immediate Help and feedback Character-based screens Screen locations are plotted using columns and lines Use screen display layout forms Messages typically on top or bottom line Graphical screens Screen locations are plotted in inches or other units More flexible designs are possible Click to see Figure 6-36

Designing Screen Output Character output High-resolution monitors allow more flexibility Display must be clear and easy to read Fonts and typefaces must be chosen carefully Click to see Figure 6-37 Click to see Figure 6-38

Designing Screen Output Character output High-resolution monitors allow more flexibility Display must be clear and easy to read Fonts and typefaces must be chosen carefully Screens vs. printed output Information might need redesign for smaller screen Multiple screens might be necessary Columnar or tabular designs are possible Click to see Figure 6-39 Click to see Figure 6-40

Designing Screen Output Graphical output Graphical displays can be very effective Many formats are possible Click to see Figure 6-40

Designing Screen Output Graphical output Graphical displays can be very effective Many formats are possible Pie charts Maps Bar charts Area charts Scatter diagrams Use descriptive titles, label each axis, and include a legend Click to see Figure 6-41 Click to see Figure 6-42

Designing Screen Output Special effects Character-based systems can use special effects High brightness Blinking Reverse video Use of different colors for emphasis Graphical environment provides options Command buttons Boxes and borders Unlimited use of color Custom menus, icons, and multiple windows Click to see Figure 6-43

Designing Other Outputs Output to tapes and disks In an integrated environment, data transfer is handled by interactive network design In other cases, data transfer uses tapes or disks Output from one program can be input to another An output file format is a data structure that can be understood by another program or system Tape or disk output design must calculate file volume

Designing Other Outputs Other output media Format and contents depend on the output device and its requirements Various output options exist Plotter output Series of commands is formatted for the specific plotter being used Computer output microfilm (COM) Output is recorded as images on roll or sheet film Data scanned/stored in digital form

Output Control Output integrity Ensure output is correct, complete, & secure Include appropriate titles and dates on reports Number pages consecutively Identify the end of each report Print/reconcile control totals/record counts Review error reports for possible causes Create error file to flag uncorrected/reentered records

Output Control Output security Protects privacy rights and proprietary data Important tasks to carry out Control the number of report copies Distribute reports only to authorized users Store sensitive reports in secure areas Label all pages of confidential reports Burn/shred sensitive reports & other output Inventory blank checks regularly Store signature forms securely

Automated Design Tools Report generators Included in CASE tools & database programs Powerful, easy-to-use features Enter constant information (titles/headings) Specify a print position for each item Use field sizes from data dictionary to create a design Produce a report definition Creates program code that can be modified

Automated Design Tools Screen generators Similar to report generators Create displays using onscreen layout tools

Automated Design Tools Completing the report and screen designs Ensure consistency with data dictionary Automate routine design tasks Produces rapid results Does not guarantee good design Still must know and apply effective design to produce reports and screens that satisfy user requirements

SOFTWEAR, LIMITED SWL development team begins system design work on the new information system Rick will concentrate on the payroll system Carla will design the ESIP outputs ESIP Deduction Register ESIP Payment Summary Transmittal checks to credit union and Stock Purchase Plan ESIP accounting summary

SOFTWEAR, LIMITED Carla’s tasks Reviewed documentation from systems analysis phase Used a report generator to develop a design Monthly format Control break on employee SSN, with control field heading and footing Click to see Figure 6-44

SOFTWEAR, LIMITED Carla’s tasks Reviewed documentation from systems analysis phase Used a report generator to develop a design Monthly format Control break on employee SSN, with control field heading and footing Used actual and test data for mock-up report Click to see Figure 6-45

SOFTWEAR, LIMITED Carla’s tasks Revised the design in response to input from Mike Feiner Click to see Figure 6-46

SOFTWEAR, LIMITED Carla’s tasks Revised the design in response to input from Mike Feiner Developed the ESIP Payment Summary as an accounting control report Click to see Figure 6-47

SOFTWEAR, LIMITED Results of the presentation The next step Recommendation was approved Top managers indicated support for the project The next step Negotiate a contract with Pacific Software Solutions for purchase of the payroll package Begin systems design work for the ESIP system