1. PowerPoint Presentation for IS-207 Copyright 2006 © Michael W. Schaffer. All rights reserved. Slide 1 Systems Analysis & Design Class #5: Design and Specifications Plus notes on architecture, scalability, and etc. 7/12/2015 5:05:18 PM

2. Slide 2 Today A bit on Specifications Some data points on costs Architecture and Deployment A bit on networking and security Scalability

3. Slide 3 PDP: Specifications “How will we build it?”, “What will it cost?” Who: Architects and Designers, QA, PM Design data architecture, component interfaces, internals of interesting elements QA is key player, to audit and align specifications to requirements. Brevity helps. Ensure review with a formal feedback processes. Refine schedule and costs, bottom-up schedule definition and buy-in.

4. Slide 4 Know your Constraints Expectations have been set on ROI, which imply the cost & schedule. The task now is to design complete solutions to the requirements, and build out a schedule that holds to the original.

5. Slide 5 Purpose of the Specification Drive detailed technical planning to expose all unknowns & risks. Create documents that answer all technical issues of “how?”. Create a document that enables testing, aligned to requirements. Create a detailed implementation plan with costs.

6. Slide 6 Size Matters Specifications should help development, not get in the way. High-level languages can make some specifications redundant. Focus on the communication needs of the project – “less can be more.”

7. Slide 7 Buy vs. Build Code is expensive: a very thin line between code as an asset, and code that is a liability Long-term value of the code? Available in the market? Core to business, or context?

8. Slide 8 Core vs. Context Your overall system is a collection of components: build for Competitive Advantage. Code you develop that is merely “context” is a distraction. What separates your business from your competition?

9. Slide 9 Toolset of Implementation Standards at your company already established? Skill-set among the existing staff? License costs? Appropriate to the tasks-at- hand?

10. Slide 10 Open Source Lots of solutions available from the Open Source community LAMP: Linux, Apache, MySQL, PHP DNS Servers, Monitoring systems Tons of Perl Using Open Source implies on- going support and maintenance.

11. Slide 11 Example: Text Search Alibris is considering a new Text Search engine. Current solution has issues … FAST, Verity, Endeca: about $300k- $500k in license costs. Lucene: Open Source Text Search  Requires much more engineering, and on-going updates and maintenance.

12. Slide 12 User Interface – Authority? Clear roles and responsibilities Everyone has an opinion: who owns the decision and authority? IA: Information Architecture … is it design, engineering, or both? Management sets the tone!

13. Slide 13 User Interfaces Your UI team holds lots of cards How complex the interface? What tools required to implement? Who builds it (HTML from development, or design shop)? What constraints on the design?

14. Slide 14 Storyboarding In the text, and a very useful exercise. Goes hand-in-hand with Use Cases. Not about layout at first, but grows to include it. Start as white-board, evolve to prototype.

15. Slide 15 UI: Some Obvious stuff KISS: “Keep it Simple, Stupid!” Is there such a thing as a design that is too straight-forward? Error checking at point-of-input Clarity of flow – avoid context switches Above the fold

16. Slide 16 Architecture Options Server-only Legacy … Client-only Installed, local stuff Appropriate for games, tools Stand-alone products (CD-based)

17. Slide 17 Architecture Options – II Client-server Fat client, private protocols Full control over PC, rich tools.

18. Slide 18 Architecture Options – III Web-based Client side: Browser, plus HTTP server + DBMS server … or HTTP server + Application Servers + Database Server

19. Slide 19 Architecture Options – IV Thin client = low-hassle Lots you can do in a browser without getting too complex Think about deployment carefully Java on the client is still a bit pokey You are relying on the local Java Virtual Machine

20. Slide 20 Scalability – Interface Servers Interface: stateless aspects are easy to scale - pool servers. Assumes HTTP servers hold no data.

21. Slide 21 Scalability – Data Store A bit harder to scale, as data needs to stay in sync. We use database replication, one-way … “master-slave”.

22. Slide 22 Replication Pros and Cons Pros: Real-time replication Optimized on target servers Cons: Can be hard to manage Multiple server licenses

23. Slide 23 What Software Licenses Cost Microsoft SQL Server $5k per CPU for “Standard” $25k per CPU for “Enterprise” General Ledger package for a Mid-size business: $50k - $100k Search engine: $50k-$300k

24. Slide 24 What People Cost Varies a ton, but: Developers: $55k - $120k QA Staff: $45k-$80k Project Mgrs: $65k-$90k Creative: $50k - $100k+ Add benefit costs, plus ~20%

25. Slide 25 What Hardware costs HTTP server, w/o storage 1-U, dual CPU, RAM: ~$3k Database server with 1 Tb fiber ~$15k for host ~$25k for fiber controller & enclosure, with 16 drives

26. Slide 26 Architecture – Logical DMZ

27. Slide 27 Architecture – Physical

28. Slide 28 Architecture – Clusters

29. Slide 29 Data Sizing Estimate the size of your data. Growth per minute/day/week? Indexing needs more space too Space is cheap, but adding to a production system is not. Backups?

30. Slide 30 Data Life Cycle Your system collects and produces data … how much? Does data stay valuable? When should it be archived? When should it be deleted? How much is too much?

31. Slide 31 Summary … These few sessions have been about communication. Your project is a reflection of the team that is created. The more effective the team, the more effective the project. Do not let technology drive the process.

32. Slide 32 Questions? Comments? Your projects?