[% META title = "Defining Service Expectations and Measurements" %]
<H1>Service Level Agreements</H1>
<H2>Simple SLAs</H2>
<p>
A <em><a href="http://en.wikipedia.org/wiki/Service_level_agreement">Service 
Level Agreement</a> (SLA)</em> is a formal definition for a service 
contract. The most important target is the <em>Turn-Around-Time</em> &mdash; the time 
to complete a request.
</p>

<p>
We measure a service level is a percentage of requests that are resolved 
within a given time. However, in order to balance work priorities, we can 
assign a severity to a tickets based upon business needs, and assign a 
different SLA target for each severity. For example, we may chose three 
(relatively simple) severities:
</p>

<dl>
<dt class="severity-critical">Critial</dt>
<dd class="severity-critical">An issue that is of major impact, cost, or effect. This may be measured as lost revenue, wasted (staff) time, or branding impact. </dd>
<dt class="severity-normal">Normal</dt>
<dd class="severity-normal">Almost everything that happens is Normal.</dd>
<dt class="severity-minor">Minor</dt>
<dd class="severity-minor">Background tasks for which there is no pressing time need to get them done.</dd>
</dl>

<p>
I will chose a critical issue as:
</p>
<ul>
<li>impacting revenue by more than $1,000/day, or
<li>affecting 3 or more staff, or 
<li>giving any negative brand impact to 3 or more people (external customers)
</ul>

<p>
When a request (ticket) is submitted to the system an immediate Auto 
Response is generated so the requestor knows their issue has been logged, 
however this gives no assurance to the requestor that their issue has 
been reviewed by a human and scheduled for action. Luckily, we can do 
this automatically when we assign (take) and priorities (set the custom 
field of severity) the ticket. If we want we could also put a time estimate 
in at this stage...
</p>

<p>
To determine our ability to adequately perform our work, we can define 
our SLA, per severity as outlined above, as a time to:
</p>

<ul>
<li>respond to the user, and a percentage of tickets that we want to meet this time
<li>resolve the issue, and a percentage of tickets that we want to meet this time
</ul>

<table>
<caption>Simple SLA per Severity</caption>
<tr><th>Severity</th><th>Target time to respond</th><th>Target time to resolve</th></tr>
<tr class="severity-critical"><td>Critical</td><td>1 hour</td><td>1 day</td></tr>
<tr class="severity-normal"><td>Normal</td><td>1 hour</td><td>7 day</td></tr>
<tr class="severity-minor"><td>Minor</td><td>1 hour</td><td>None</td></tr>
</table>

<p>
We set the target time to resolve as the same for all Severities as we won't 
know the Severity or the resolution time until we have reviewed the ticket 
initally. So we should immediately classify, and (auto) respond to the 
requestor at that time.
</p>

<H2>Getting more complex</H2>

<p>
Not everything is deserving of 24x7 cover. No one cares if the office 
copier stops working at 3am; but you do care at 9am until 6pm. Alternatively you would be concernced about your e-Commerce application going down at any time.
</p>

<p>
If we have offices in multiple time zones (eg: London, New York) 
then there may be some services that are in use during your 
<em>Global Business Hours</em>, and some during your 
<em>Local Business Hours</em>.  To deal with this we'll chose three 
classes (levels) of services to indicate an importance, and we select 
what services belong to which classification:
</p>
<dl>
<dt class="bg-color-gold">Gold</dt>
<dd class="bg-color-gold">24 x 7 x 365. We care about this big-time; this is your web site (brand damage if it goes down) or your eCommerce application (money lost if it goes down)
<ul>
<li>Ecommerce web site/engine
<li>Corporate web site
<li>Email
<li>Building security system
</ul>

</dd>
<dt class="bg-color-silver">Silver</dt>
<dd class="bg-color-silver">Global Business Hours, typically Monday - Friday. This may be your intranet or other internal global resources
<ul>
<li>Intranet System
<li>Finance system
<li>ECommerce back ends
</ul>

</dd>
<dt class="bg-color-bronze">Bronze</dt>
<dd class="bg-color-bronze">Local Business Hours, normally 9am - 6pm. This would be your office printer, phone system, etc
<ul>
<li>Printer(s)
<li>Phone systems
<li>Cell/mobile phones
</ul>

</dd>
</dl>


<p>
For each of these Class of service we have our three (or more) severities, so we can now define our target response and resolution times, and our target SLA 
percentage to meet this.
</p>

<table>
<caption>Complex SLA per Service Class per Severity</caption>
<tr><th>Class</th><th>Severity</th><th>Response time</th><th>Response SLA</th><th>Resolve time</th><th>Resolve SLA</th></tr>

<tr class="severity-critical"><td rowspan=3 class="bg-color-gold">Gold<br /><small>24 x 7</small></td><td>Critical</td><td>1 hour</td><td>90%</td><td>2 hours</td><td>90%</td></tr>
<tr class="severity-normal"><td class="severity-normal">Normal</td><td>1 hour</td><td>90%</td><td>1 day</td><td>90%</td></tr>
<tr class="severity-minor"><td class="severity-minor">Minor</td><td>1 hour</td><td>90%</td><td>None</td><td>-</td></tr>

<tr class="severity-critical"><td rowspan=3 class="bg-color-silver">Silver<br /><small>Global business hours</small></td><td>Critical</td><td>1 hour</td><td>90%</td><td>24 global business hours</td><td>90%</td></tr>
<tr class="severity-normal"><td>Normal</td><td>1 hour</td><td>90%</td><td>96 global business hours</td><td>90%</td></tr>
<tr class="severity-minor"><td>Minor</td><td>1 hour</td><td>90%</td><td>None</td><td>-</td></tr>

<tr class="severity-critical"><td rowspan=3 class="bg-color-bronze">Bronze<br /><small>Local business hours</small></td><td>Critical</td><td>1 hour</td><td>90%</td><td>24 local business hours</td><td>90%</td></tr>
<tr class="severity-normal"><td>Normal</td><td>1 hour</td><td>90%</td><td>96 local business hours</td><td>90%</td></tr>
<tr class="severity-minor"><td>Minor</td><td>1 hour</td><td>90%</td><td>None</td><td>-</td></tr>
</table>

<p>
The default ticket has all these fields, but we need to extend with a 
custom field for Severity and Service.
This will be a <a href="CreatingCustomFields.html">Custom Field</a>.
</p>