1. Management Paper – Commercial Spreadsheet Review Simon Murphy simon.murphy@codematic.net Developer – Codematic Ltd

2. Spreadsheet background Up to 200 Mb size Up to 1 Million formulas 1-10,000 unique formulas 5-10,000 lines of VBA £1M to 100’s of Billions in values Often linked to other technologies such as OLAP, ADO, COM or.net etc. Finance, Banking and Sales and Marketing areas

3. Agenda Introduction Scope of Review Stages of Review –Spreadsheet in context –File Review –Workbook Review –Sheet Summary –Inter Sheet Interactions –Cell/Block level Relationships Summary Conclusion Any Questions?

4. Introduction - Spreadsheet Quote Program Manager to Steering Committee: “We can build this system in – a large consolidation software package –, it will take 2 developers 6 months and cost half a million. Or 1 developer can do it in Excel in 10 weeks for 30 thousand.”

5. Introduction - Spreadsheet Definition 2006 - Organisational –Spreadsheet – the product of one or more people following some sort of process to a deadline. 2005 - Technical –Spreadsheet – powerful and flexible, single end user, analysis and presentation tool, optimised for speed of initial development.

6. Scope of Review The review is pre-sales (i.e. ‘free’) The aim of the review is to estimate the time to repair, enhance, or migrate the spreadsheet. Totally NOT any sort of audit. Target time is 2-4 hours. Explicit assumption the spreadsheet is fit for purpose currently. Assumes no useful documentation.

7. Spreadsheet in Context What is it used for? How important is it? How connected is it? Is network access required?

8. File Review Virus scan Workbook file properties Remove protection

9. Workbook Review - 1 Open with VBA disabled Check any VBA code (and XLMs) for security issues

10. Workbook Review – 2 Review summary metrics

11. Workbook Review - 3 Run XLAnalyst for brief summary High score may make review harder

12. Workbook Review - 4 Glance at unique formulas

13. Sheet Summary Once sentence summary (if possible) of what the sheet does. Added to navigation sheet

14. Inter Sheet Interactions Data flows Left hand are pure children/source sheets Right hand side are unconnected (by basic formulas)

15. Inter Sheet Interactions

18. Cell/Block level Relationships Review named ranges (Free tool - Google for NameManager)

19. Cell/Block level Relationships Quick value type overview

20. Cell/Block level Relationships Review the actual formulas for shapes Finally work though a few formulas

21. Cell/Block level Relationships Real world flows

22. Cell/Block level Relationships Real world flows

23. Some Fun Formulas 1.=IF(AND(AND(AND(AND('s29'!AK50=0,'s29'!AK51=0,'s2 9'!AK54=0,'s29'!AK55=0)))),"N","") 2.=IF(AND($E$45="a",AF9>0),AK45,IF($E$45="M",AK45 /12*$E$9/30,IF(AND($E$45="Q",AF9>0),IF(AK50=12,A K45/4,IF(AK50=11,AK45*3/11,IF(AK50=10,AK45*2/10, 0))),AK45*0))) 3.=IF(AND(I89<>0,I88=0,SUM($U$88:U88)=0),1,IF(OR( ISERROR(I89),NOT(ISNUMBER(I89))),"Error",0)) 4.=+B49*(0.173076923076923) 5.=+E27*SUM(D5/G5) 6.=SUM('PayEx'!$U5*'PayEx (Annual) '!$J$5)*(100%+'% Increase in x'!CH7) 7.=G43*1000/G83

24. Last one =E111+E118+E119+E120+E121+E122+E 123+E124+E125+E185+E186+E187+E18 8+E189+E190+E191+E216+E217+E218+ E219+E220+E222+E223+E227+E233+E2 34+E240+E241+E246+E468+E469+E470 +E471+E472+E475+E533+E534+E535+E 536+E537+E540+E579+E580+E581- E257-E252

25. Summary Brief overview of one commercial review process Aim to drill into a spreadsheet one level at a time Target is to make changes to a live spreadsheet without introducing new errors

26. Conclusion Using a few basic tools and a structured approach it is possible to gain a reasonable understanding of a spreadsheet within commercially viable timescales.

27. Questions? simon.murphy@codematic.net –Spreadsheet consulting, reviewing, maintaining, rescuing, migrating, add-in development etc. Websites –www.codematic.net –www.xlanalyst.co.uk