1. Paul Alexander 2 nd SKADS Workshop 10-11 October 2007 SKA and SKADS Costing The Future Paul Alexander Andrew Faulkner, Rosie Bolton

2. Paul Alexander 2 nd SKADS Workshop 10-11 October 2007 Costing The SKA Our aim is to deliver a final SKA – No point in design without costing –Concepts and designs have to fit within a realistic budget when costed honestly At this stage of the project the priority is “cost modelling” –Compare and contrast design options –Identify cost scalings and cost drivers  modify design SKADS is playing a major role –First fully costed design for the SKA – Benchmark Scenario –Now coordinating the collaboration between SKADS, ISPO team, AU and SA costing teams in a single SKA costing exercise and tool – whole process overseen by ISPO

3. Paul Alexander 2 nd SKADS Workshop 10-11 October 2007 Design and Costing SKADS is contributing very significantly to the SKA cost model and tool and next generation tools and concepts SKADS deliverable is a fully costed design –Excellent progress towards the main SKADS deliverable –Design and costing and evolution of the SKADS Benchmark Scenario is a continuing process and will continue until at least the end of SKADS –Rosie Bolton will talk tomorrow about the details of the costing process in SKADS –I will discuss the process and the tools

4. Paul Alexander 2 nd SKADS Workshop 10-11 October 2007 Completed Design and Costing Exercise – 1 Initial D&C meetingNovember 2006 Work on details of system blocks D&C Review meeting15 January 2007 Preparing written work Initial Drafts9 February Consolidating paper Final Draft 21 February Approval of Paper28 February Publication of Paper7 March 2007 Revisit for SKA Design Specification Review

5. Paul Alexander 2 nd SKADS Workshop 10-11 October 2007 Not addresses in SKA Memo 93 –Correlator design and costs –Central processing hardware, model and costs –Phased development of Benchmark Scenario costed Identify scalings throughout the design Better models and methods for: –Dishes –Accounting practices –Uncertainty calculations –Optimisations and tradeoffs Needed for stage 2 ISPO team collaboration

6. Paul Alexander 2 nd SKADS Workshop 10-11 October 2007 Timetable for Stage 2 Start second Design and costing exercise12 September 2007 Update those areas not properly analysed in stage 1 ISPO preliminary SKA phase-1 and SKA specsMarch 2008 SKADS input on costed design incorporating AAs ISPO final SKA phase-1 and SKA specsMarch 2009 Detailed SKADS input Prepare for SKADS deliverable

7. Paul Alexander 2 nd SKADS Workshop 10-11 October 2007 Costing Methodology Ideal is to have a single approach to costing within the SKA project –Share expertise across the entire project –Have a single tool we can use for comparative purposes –Collaboration between SKADS, ISPO, AU and SA costing teams –Two weeks work + meeting in Cambridge in June/July

8. Paul Alexander 2 nd SKADS Workshop 10-11 October 2007 SKADS costing in SKA Memo 93 used a spreadsheet approach –Good: exposed costs to everyone involved in the project –Good: easy to use and modify by non-experts –Good: mapped costing onto the design elements of the telescope and kept the model intimately linked to the design –Bad: difficult to simulate, do montecarlo uncertainty modelling –Bad: consistency and error checking done by hand –Bad: lacks flexibility and poor scaling of elements of the design The approaches

9. Paul Alexander 2 nd SKADS Workshop 10-11 October 2007 ISPO modelling, SKA Memo 92 –Good: simulation environment with montecarlo modelling –Good: scaling and model exploration –Good: consistency and error checking –Bad: difficult for non experts to alter –Bad: assumptions not easily exposed to the user – the tool can be dangerous if the underlying model is wrong or not appreciated by the users –Bad: difficult to incorporate a real design or consider effects of design changes SA costing for MeerKAT –Good: used same original code base as ISPO –Good: excellent tools to visualise outputs –Bad: see ISPO The approaches

10. Paul Alexander 2 nd SKADS Workshop 10-11 October 2007 Structure of a new tool SKA realisation Design Block Component

11. Paul Alexander 2 nd SKADS Workshop 10-11 October 2007 Adopt the SKADS high-level view –System consisting of Design Blocks we combine together to form a realisation of the telescope –Design blocks use costed components and/or cost models which are determined by domain experts –The costing process involves everyone Use a modified ISPO code base for the implementation + new UI –Python code (initially) implements the specifications / design of each design block –Standard software tools provided to ensure consistency, error checking, uncertainty modelling –GUI enables non-experts to browse, modify and develop components and design blocks (some python code needed) Build in the MeerKAT approach to visualisation Structure of the new tool

12. Paul Alexander 2 nd SKADS Workshop 10-11 October 2007 Design Block reporting and design structure Cost modelling code (python or …) Library of DBs and components (xml format) GUI interface

13. Paul Alexander 2 nd SKADS Workshop 10-11 October 2007 Structure of the new tool

14. Paul Alexander 2 nd SKADS Workshop 10-11 October 2007 Example Model: Aperture Array

15. Paul Alexander 2 nd SKADS Workshop 10-11 October 2007 GUI Snapshot

16. Paul Alexander 2 nd SKADS Workshop 10-11 October 2007 The Repository Develop libraries of components and design blocks in a repository Domain experts review, extend and modify these Expect an SKA wide repository and also repositories local to other projects one at least Individuals can have their own library or modify existing system realisations, design blocks and components

17. Paul Alexander 2 nd SKADS Workshop 10-11 October 2007 Using the Model Astronomer –Use an existing design of the SKA and investigate cost and performance tradeoffs within the design, output performance information/statistics System designer or expert radio astronomer –Construct SKA realisations (systems) out of existing design blocks and components Engineer –Develop and review design blocks and components

18. Paul Alexander 2 nd SKADS Workshop 10-11 October 2007 Timeline – Best Efforts End September –Include basic AA description into costing tool Mid October –GUI to browse component library –Underlying change to system architecture Mid November –GUI to browse / modify design block library January/February 2008 –First release of an integrated tool

19. Paul Alexander 2 nd SKADS Workshop 10-11 October 2007 Conclusions Initial design and costing has been a very good first step towards our final deliverable We have learnt a great deal about feasible and affordable designs SKADS coordinating intercontinental effort to deliver the SKA costing tool Work to date crucial in establishing AA technology as a core technology for all SKA options