1 Project Management Example Solving Sudoku

2 What is Sudoku?  Sudoku is a game with 9 columns and 9 rows and 9 “boxes” composed of a 3 x 3 Grid  Numbers from 1 to 9 should be entered once in each column, row and box  All games have some numbers already entered

3 Sample Sudoku Game

4 Step 1: Set the Goal Create a Sudoku Solver that solves 100% of the Games fast

5 Step 2: Determine the steps

6 Step 2a: Create an input screen – which allows the easy entry of numbers into a 9 x 9 grid Solution: Use an Excel spreadsheet

7 Step 2B: Select Programming Language Solution: Visual Basic is available within Excel as a programming language

8 Step 2c: Design subroutines required to complete project Main Module o Update by rows – create subroutine o Update by columns – create subroutine o Update by boxes – create subroutine o Add additional subroutines as needed o Add final subroutine to solve sequentially o Evaluate the results of each subroutine (Win, Lose or Draw)

9 Step 3: Implement the plan Write the subroutines

10 Step 4a: Purchase of Sudoku puzzle book of 320 games split into 90 easy games, 90 medium games, 90 hard games, 50 very hard games. Step 4: Test the Results Were all the games solved?

11 Step 4b: Evaluate and review Testing Results Easy: 90 of 90 solved Medium: 75 of 90 solved Hard: 38 of 45 solved Tests stopped here Conclusion: 1 More modules need to be added 2 Sequential testing takes too long

12 Step 2d: Design more Subroutines or change existing routines to solve more puzzles Viewed Doubles by Row, Column, Boxes Hidden Pairs by Row, Columns, Boxes

13 Step 3A: Write the Code Added the Additional Tests needed and discovered a quicker way to solve the puzzles in one of the modules (Level 5 Sequential Testing )

14 Step 4c: Evaluate and review Test Results 1 of the 32 games was not solved – due to duplicate solutions. More games are solved - but 32 games were remaining for sequential testing.

15 Step 1a: Revise the Goal to be more specific New Goal: Solve 100% of the Games with less than 2% of games solved sequentially. This will speed-up finding the solutions

16 Step 2e : Design additional Subroutines o Find additional patterns based on data. o Check Internet for additional ideas on logic used for elimination of possibilities within cells o Review Sequential testing module to determine if this can be further rewritten to work better/faster

17 Step 3B: Write the Code

18 Step 4c: Evaluation of test results on 16 new modules Medium: 6 Hard: 3 Very Hard: 8 Remaining unsolved at completion of level 3 tests: 17

19 2e: Design: Modify the order of the subroutines to speed up the finding of the solutions of programs Level 1Level 2Level 3 Level 5 (Sequential) # of Games # of Tests39 (3 + 6) 25 (16+19) 2.3 x 25

20 2f: Design New Pattern Emerging Noticed more of hard games were solved than medium games Are all of the modules working properly? Is there additional logic that could be tested for but were missed?

21 2g: Design Found New Logic!!! Wrote 2 add’l subroutines and added to level 2 All but 3 of level 3 games were solved by new level 2 subroutines. Possible to eliminate Level 3 and rely on Level 5 as a catch all. Number of games left for level 5: 3 Number of Sequential tries for Level 5: reduced to 1

22 3c: Write the Code

23 4f: Review and Evaluate Testing Results Level 1Level 2 Level 3 & 5 (Sequential) # of Games # of Tests3 11 (3 + 8) 1 x 25 All solved on 1 st try

24 Step 5: Goals Reached Project Completed The End

25 Tech Specifications Machine Specification – Pentium Core Duo running at 2.4 Megahertz The Program was written in Visual Basic within Excel 2003 Average Time To Solve Maximum Time To Solve Level Seconds5 Seconds Level 59 Seconds1 Minute Level 612 Seconds10 Minutes Estimate

26 Last Word All Games that I found anywhere (in Books, On-Line or in Newspapers were solved at Levels 1-5 Level 6 was added as a “Last Resort” Any Game that was “Incomplete” at end of Level 5 was solved in Level 6. Level 6 was tested and found 1 solution with as little as 9 cells in the Sudoku Grid. For Games with multiple solutions (Level 5 or 6) – only 1 solution was displayed

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