Friday, March 20, 2009

Case Studies in Enterprise Architecture

A few nights ago, I attended a fascinating evening with Wayne Horkan, the CTO of Sun Microsystems for UK and Ireland, who presented his views on Enterprise Architecture. The event was jointly organised by IET, the BCS Manchester branch with a pitch for the recently formed BCS Enterprise Architecture Specialist Group forming the warm act before Wayne's presentation.

Wayne presented his experience in 3 (anonymous) organisations who experienced difficulties in their approach to delivering an enterprise architecture. The problems could easily be addressed by recognising the key and important role of enterprise architects who maintain an understanding of the business context, provides domain knowledge and ensure that the architecture and supporting IT remains aligned with the business. 

In assessing any programme, a simple 4 stage approach is followed:

  1. Gather the facts by a series of interviews and information gathering. This includes understanding the current 'as is' enterprise architecture, the current IT/IS setup and the 'vision' for the future.
  2. Analyse the data
  3. Determine the key conclusions/recommendations and the way foward. This includes establishing the order of change to ensure that the changes deliver value to the organisation without destablising the exsiting organisation.
  4. Assess the project against the five key areas of likely project failure:

  • Strategy. Is it really needed? Why is it needed now? Will it deliver a realistic ROI?
  • Contractual. Is the contract, including the financial elements, appropriate defined and achievable?
  • Process/procedures. Are we in control or out of control?
  • Politics and personnel. Is there buy-in from all concerned/affected?
  • Technical and architectural. The least likely cause of project failure (apparently) but need to ensure that the right resources are available in order to deliver the right solution.

Wayne concluded with a number of best practices based on his experiences with these (and other) organisations:

  1. Ignore the religious arguments about which framework to use. Just pick a single framework and stick with it. Most organisations use a blend of Zachman (artefact focused) and TOGAF (procedurally focused). None of the frameworks provide a magic bullet with which success is guaranteed.

  2. Obtain sponsorship from key stakeholders. The stakeholders must have a strategy for the business, which may change over time, that is communicated to the EA team.

  3. The EA team must continually:

  • Remain delivery focused, providing value to the organisation

  • Involve the whole team (consisting of Enterprise, Infrastructure and Application architects) in all decisions, ensuring that cross-team communication is integral to the team (no silos)

  • Ensure that there is the right mix of technical skills to deliver the right architecture

  • Obtain and foster Sponsorship, Sponsorship, Sponsorship without which a programme is likely to fail

  • Keep aligned (and checking) with the business strategy

As a reality check, Wayne highlighted that the current economic climate now requires that the investment in enterprise architecture must be seen to deliver value far more quickly (i.e. in the matter of months rather than years) to the business than has previously been tolerated.

The session was well attended and left the audience with much to consider in future projects.

The slides, and Wayne's personal views on the session are contained here.

Sunday, March 1, 2009

Going forward with PHP

I run a number of websites which provide a daily update of a shareprice together with the value of the shareprice converted to a loical currency (e.g. £, $, Aus$). When I started, I selected Perl as my scripting language which provided me the necessary facilities (the LWP package) to retrieve a shareprice from the Yahoo finance site. I used the URL'.$stock_symbol
as my data page which returned the share's closing price and other useful information.

I also generated a graph which showed the historical share price, relative to one of the major indices (e.g. FTSE, CAC40).

As I couldn't host my scripts on my web site, I was required to run a number of Perl scripts to generate updated files and then upload the files to the webhost. I wrapped the scripts in a DOS batch file and set up a scheduled task (under Windows) to run the scripts every weekday after the markets had closed.

This worked very well, most of the time. However it suffered from a number of problems. If I wasn't around, and didn't turn my PC on, then the scripts didn't run and the shareprice wasn't updated. I also suffered from some problems with my web connection which meant that the scripts didn't run as expected and I obtained a zero shareprice.

I had been wondering how to make the system better and less dependent on my PC being turned on. Most ISPs that I have experienced don't allow the LWP package to be installed as part of the standard Perl installation, presumably based on security concerns. I therefore considered alternative scripting languages. I had already seen Python at SPA2008 and was keen to try and see Python was a suitable replacement. However, my web host didn't offer Python in its standard configuration, but did offer the other P language, PHP. 

PHP treats a URL as a filename and does not appear (in the standard configurations installed on webhosts) to suffer from the security constaints that Perl installations suffer. A simple function retrieves the values for a stock symbol returning the parameters in an array.
function get_share_price($stock_symbol)
$filesize = 2000;
$handle = fopen($url, "r");
$arr = fgetcsv($handle , $filesize , ',');
return $arr;
This resolved the problem of updating a daily share price, and also offered the opportunity for offering live share price updates (subject to the market delays which free services such as Yahoo suffer - at  least 15 minutes delay).

To resolve the historic share price required PHP again but this time with a different Yahoo feed which I had only recently discovered, the ichart interface which returns the data as a stream of  CSV separated values. 

function plot($numdays, $stock_symbol)
// Get current date
$d--; // Months are 0-11
$arrResult = array();
$handle = fopen($yahoostr, "r");
if( $handle ) 
while (($data = fgetcsv($handle, 1000, ",")) !== FALSE) 
if ($n == 0)
$n=1; // Ignore header row
$arrResult[] = $data;
// Select data subset
// Determine chart scale
foreach ($arr1 as $data ) 
$min = min($data[4], $min); 
$max = max($data[4], $max); 
// Data is currently stored Newest-> Oldest.
$arr = array_reverse($arr1);
// Now plot data (date in element 0, value in element 4).

In processing the data, I discovered a number of additional PHP features, including
  • array_reverse -to reverse an array (required because the Yahoo data is returned with the most recent data first)
  • array_slice -to take a subset of an array
  • min, max - to determine the minimum and maximum values (how many times has code for this suimple function been written!)
This meant that I had the data in a format which I could then process to produce a graph (dynamically). Now the next question was to select a suitable graphing package which offered a good PHP interface. But that is another story.