Common Software Errors

Type of Errors

• User Interface Errors

• Error Handling

• Boundary related errors

• Calculation errors

• Initial and Later states

• Control flow errors

• Errors in Handling or Interpreting Data

• Race Conditions

• Load Conditions

• Hardware

• Source, Version and ID Control

• Testing Errors

Let us go through details of each kind of error.

User Interface Errors

Functionality
Sl No	Possible Error Conditions
1	Excessive Functionality
2	Inflated impression of functionality
3	Inadequacy for the task at hand
4	Missing function
5	Wrong function
6	Functionality must be created by user
7	Doesn't do what the user expects

Communication
Missing Information
Sl No	Possible Error Conditions
1	No on Screen instructions
2	Assuming printed documentation is already available.
3	Undocumented features
4	States that appear impossible to exit
5	No cursor
6	Failure to acknowledge input
7	Failure to show activity during long delays
8	Failure to advise when a change will take effect
9	Failure to check for the same document being opened twice
Wrong, misleading, confusing information
10	Simple factual errors
11	Spelling errors
12	Inaccurate simplifications
13	Invalid metaphors
14	Confusing feature names
15	More than one name for the same feature
16	Information overland
17	When are data saved
18	Wrong function
19	Functionality must be created by user
20	Poor external modularity
Help text and error messages
21	Inappropriate reading levels
22	Verbosity
23	Inappropriate emotional tone
24	Factual errors
25	Context errors
26	Failure to identify the source of error
27	Forbidding a resource without saying why
28	Reporting non-errors
29	Failure to highlight the part of the screen
30	Failure to clear highlighting
31	Wrong/partial string displayed
32	Message displayed for too long or not long enough
Display Layout
33	Poor aesthetics in screen layout
34	Menu Layout errors
35	Dialog box layout errors
36	Obscured Instructions
37	Misuse of flash
38	Misuse of color
39	Heavy reliance on color
40	Inconsistent with the style of the environment
41	Cannot get rid of on screen information
Output
42	Can't output certain data
43	Can't redirect output
44	Format incompatible with a follow-up process
45	Must output too little or too much
46	Can't control output layout
47	Absurd printout level of precision
48	Can't control labeling of tables or figures
49	Can't control scaling of graphs
Performance
50	Program Speed
51	User Throughput
52	Can't redirect output
53	Perceived performance
54	Slow program
55	slow echoing
56	how to reduce user throughput
57	Poor responsiveness
58	No type ahead
59	No warning that the operation takes long time
60	No progress reports
61	Problems with time-outs
62	Program pesters you

Program Rigidity
User tailorability
Sl No	Possible Error Conditions
1	Can't turn off case sensitivity
2	Can't tailor to hardware at hand
3	Can't change device initialization
4	Can't turn off automatic changes
5	Can't slow down/speed up scrolling
6	Can't do what you did last time
7	Failure to execute a customization commands
8	Failure to save customization commands
9	Side effects of feature changes
10	Can't turn off the noise
11	Infinite tailorability
Who is in control?
12	Unnecessary imposition of a conceptual style
13	Novice friendly, experienced hostile
14	Surplus or redundant information required
15	Unnecessary repetition of steps
16	Unnecessary limits

Command Structure and Rigidity
Inconsistencies
Sl No	Possible Error Conditions
1	Optimizations
2	Inconsistent syntax
3	Inconsistent command entry style
4	Inconsistent abbreviations
5	Inconsistent termination rule
6	Inconsistent command options
7	Similarly named commands
8	Inconsistent Capitalization
9	Inconsistent menu position
10	Inconsistent function key usage
11	Inconsistent error handling rules
12	Inconsistent editing rules
13	Inconsistent data saving rules
Time Wasters
14	Garden paths
15	choice can't be taken
16	Are you really, really sure
17	Obscurely or idiosyncratically named commands
Menus
18	Excessively complex menu hierarchy
19	Inadequate menu navigation options
20	Too many paths to the same place
21	You can't get there from here
22	Related commands relegated to unrelated menus
23	Unrelated commands tossed under the same menu
Command Lines
24	Forced distinction between uppercase and lowercase
25	Reversed parameters
26	Full command names are not allowed
27	Abbreviations are not allowed
28	Demands complex input on one line
29	no batch input
30	can't edit commands
Inappropriate use of key board
31	Failure to use cursor, edit, or function keys
32	Non std use of cursor and edit keys
33	non-standard use of function keys
34	Failure to filter invalid keys
35	Failure to indicate key board state changes

Missing Commands
State transitions
Sl No	Possible Error Conditions
1	Can't do nothing and leave
2	Can't quit mid-program
3	Can't stop mid-command
4	Can't pause
Disaster prevention
5	No backup facility
6	No undo
7	No are you sure
8	No incremental saves
Disaster prevention
9	Inconsistent menu position
10	Inconsistent function key usage
11	Inconsistent error handling rules
12	Inconsistent editing rules
13	Inconsistent data saving rules
Error handling by the user
14	No user specifiable filters
15	Awkward error correction
16	Can't include comments
17	Can't display relationships between variables
Miscellaneous
18	Inadequate privacy or security
19	Obsession with security
20	Can't hide menus
21	Doesn't support standard OS features
22	Doesn't allow long names

Error Handling

Error prevention
Sl No	Possible Error Conditions
1	Inadequate initial state validation
2	Inadequate tests of user input
3	Inadequate protection against corrupted data
4	Inadequate tests of passed parameters
5	Inadequate protection against operating system bugs
6	Inadequate protection against malicious use
7	Inadequate version control

Error Detection
Sl No	Possible Error Conditions
1	ignores overflow
2	ignores impossible values
3	ignores implausible values
4	ignores error flag
5	ignores hardware fault or error conditions
6	data comparison

Error Recovery
Sl No	Possible Error Conditions
1	automatic error detection
2	failure to report error
3	failure to set an error flag
4	where does the program go back to
5	aborting errors
6	recovery from hardware problems
7	no escape from missing disks

Boundary related errors

Sl No	Possible Error Conditions
1	Numeric boundaries
2	Equality as boundary
3	Boundaries on numerosity
4	Boundaries in space
5	Boundaries in time
6	Boundaries in loop
7	Boundaries in memory
8	Boundaries with data structure
9	Hardware related boundaries
10	Invisible boundaries
11	Mishandling of boundary case
12	Wrong boundary
13	Mishandling of cases outside boundary

Calculation Errors

Sl No	Possible Error Conditions
1	Bad Logic
2	Bad Arithmetic
3	Imprecise Calculations
4	Outdated constants
5	Calculation errors
6	Impossible parenthesis
7	Wrong order of calculations
8	Bad underlying functions
9	Overflow and Underflow
10	Truncation and Round-off error
11	Confusion about the representation of data
12	Incorrect conversion from one data representation to another
13	Wrong Formula
14	Incorrect Approximation

Race Conditions

Sl No	Possible Error Conditions
1	Races in updating data
2	Assumption that one event or task finished before another begins
3	Assumptions that one event or task has finished before another begins
4	Assumptions that input won't occur during a brief processing interval
5	Assumptions that interrupts won't occur during brief interval
6	Resource races
7	Assumptions that a person, device or process will respond quickly
8	Options out of sync during display changes
9	Tasks starts before its prerequisites are met
10	Messages cross or don't arrive in the order sent

Initial and Later States

Sl No	Possible Error Conditions
1	Failure to set data item to zero
2	Failure to initialize a loop-control variable
3	Failure to initialize a or re-initialize a pointer
4	Failure to clear a string
5	Failure to initialize a register
6	Failure to clear a flag
7	Data were supposed to be initialized elsewhere
8	Failure to re-initialize
9	Assumption that data were not re-initialized
10	Confusion between static and dynamic storage
11	Data modifications by side effect
12	Incorrect initialization

Control Flow Errors

Program runs amok
Sl No	Possible Error Conditions
1	Jumping to a routine that isn't resident
2	Re-entrance
3	Variables contains embedded command names
4	Wrong returning state assumed
5	Exception handling based exits

Return to wrong place
Sl No	Possible Error Conditions
1	Corrupted Stack
2	Stack underflow/overflow
3	GOTO rather than RETURN from sub-routine
Interrupts
Sl No	Possible Error Conditions
1	Wrong interrupt vector
2	Failure to restore or update interrupt vector
3	Invalid restart after an interrupt
4	Failure to block or un-block interrupts

Program Stops
Sl No	Possible Error Conditions
1	Dead crash
2	Syntax error reported at run time
3	Waiting for impossible condition or combinations of conditions
4	Wrong user or process priority

Error Detection
Sl No	Possible Error Conditions
1	infinite loop
2	Wrong starting value for the loop control variables
3	Accidental change of loop control variables
4	Command that do or don't belong inside the loop
5	Command that do or don't belong inside the loop
6	Improper loop nesting

If Then Else , Or may not
Sl No	Possible Error Conditions
1	Wrong inequalities
2	Comparison sometimes yields wrong result
3	Not equal verses equal when there are three cases
4	Testing floating point values for equality
5	confusion between inclusive and exclusive OR
6	Incorrectly negating a logical expression
7	Assignment equal instead of test equal
8	Commands being inside the THEN or ELSE clause
9	Commands that don't belong either case
10	Failure to test a flag
11	Failure to clear a flag

Multiple Cases
Sl No	Possible Error Conditions
1	Missing default
2	Wrong default
3	Missing cases
4	Overlapping cases
5	Invalid or impossible cases
6	Commands being inside the THEN or ELSE clause
7	Case should be sub-divided

Errors Handling or Interpreting Data

Problems in passing data between routines
Sl No	Possible Error Conditions
1	Parameter list variables out of order or missing
2	Data Type errors
3	Aliases and shifting interpretations of the same area of memory
4	Misunderstood data values
5	inadequate error information
6	Failure to clean up data on exception handling
7	Outdated copies of data
8	Related variable get out of synch
9	Local setting of global data
10	Global use of local variables
11	Wrong mask in bit fields
12	Wrong value from table

Data boundaries
Sl No	Possible Error Conditions
1	Un-terminated null strings
2	Early end of string
3	Read/Write past end of data structure or an element in it

Read outside the limits of message buffer
Sl No	Possible Error Conditions
1	Complier padding to word boundaries
2	value stack underflow/overflow
3	Trampling another process's code or data

Messaging Problems
Sl No	Possible Error Conditions
1	Messages sent to wrong process or port
2	Failure to validate an incoming message
3	Lost or out of synch messages
4	Message sent to only N of N+1 processes

Data Storage corruption
Sl No	Possible Error Conditions
1	Overwritten changes
2	Data entry not saved
3	Too much data for receiving process to handle
4	Overwriting a file after an error exit or user abort

Load Conditions

Sl No	Possible Error Conditions
1	Required resources are not available
2	No available large memory area
3	Input buffer or queue not deep enough
4	Doesn't clear item from queue, buffer or stock
5	Lost Messages
6	Performance costs
7	Race condition windows expand
8	Doesn't abbreviate under load
9	Doesn't recognize that another process abbreviates output under load
10	Low priority tasks not put off
11	Low priority tasks never done

Doesn't return a resource
Sl No	Possible Error Conditions
1	Doesn't indicate that it's done with a device
2	Doesn't erase old files from mass storage
3	Doesn't return unused memory
4	Wastes computer time

Hardware

Sl No	Possible Error Conditions
1	Wrong Device
2	Wrong Device Address
3	Device unavailable
4	Device returned to wrong type of pool
5	Device use forbidden to caller
6	Specifies wrong privilege level for the device
7	Noisy Channel
8	Channel goes down
9	Time-out problems
10	Wrong storage device
11	Doesn't check the directory of current disk
12	Doesn't close the file
13	Unexpected end of file
14	Disk sector bug and other length dependent errors
15	Wrong operation or instruction codes
16	Misunderstood status or return code
17	Underutilizing device intelligence
18	Paging mechanism ignored or misunderstood
19	Ignores channel throughput limits
20	Assuming device is or isn't or should be or shouldn't be initialized
21	Assumes programmable function keys are programmed correctly

Source, Version, ID Control

Sl No	Possible Error Conditions
1	Old bugs mysteriously re appear
2	Failure to update multiple copies of data or program files
3	No title
4	No version ID
5	Wrong version number of title screen
6	No copy right message or bad one
7	Archived source doesn't compile into a match for shipping code
8	Manufactured disks don't work or contain wrong code or data

Testing Errors

Missing bugs in the program
Sl No	Possible Error Conditions
1	Failure to notice a problem
2	You don't know what the correct test results are
3	You are bored or inattentive
4	Misreading the Screen
5	Failure to report problem
6	Failure to execute a planned test
7	Failure to use the most promising test case
8	Ignoring programmer's suggestions

Finding bugs that aren't in the program
Sl No	Possible Error Conditions
1	Errors in testing programs
2	Corrupted data files
3	Misinterpreted specifications or documentation

Poor reporting
Sl No	Possible Error Conditions
1	Illegible reports
2	Failure to make it clear how to reproduce the problem
3	Failure to say you can't reproduce the problem
4	Failure to check your report
5	Failure to report timing dependencies
6	Failure to simplify conditions
7	Concentration on trivia
8	Abusive language

Poor Tracking and follow-up
Sl No	Possible Error Conditions
1	Failure to provide summary report
2	Failure to re-report serious bug
3	Failure to check for unresolved problems just before release
4	Failure to verify fixes