[OSLC] Minutes of the OSLC Estimation and Measurement Telecon, 2009-07-18, 10AM EST

Arthur Ryman ryman at ca.ibm.com
Fri Jul 17 11:57:29 EDT 2009

Attendees: AndyBerner, ArthurRyman, LawrencePutnamJr, ScottBosworth, 

See [1] for logistics.

1. Review working draft of EMS 1.0 Part 0: Primer [2] - Arthur
Provider/Consumer Architecture in EMS 1.0
We discussed the architecture of the EMS 1.0 spec, which is that the PPM 
tools are service providers and the software estimation tools are service 
consumers. We need to make this more apparent. 

We also discussed where and how resources are stored, and agreed that this 
is a separate concern from their representation. The data model is 
expressed as a collection of RDF triples which express relations bewteen 
resources. The resource URIs may be managed by a set of one or more 
servers. Statements about how long resources persist, whether they are 
copied, etc. go beyond the data model and need to be included in the 
service description where appropriate.

[ACTION] ArthurRyman to describe the architecture in an Architecture 
section near the beginning of the Primer.

Explicit Collections in Resource Design
ArthurRyman initially used explicit collection resources, e.g. a Project 
has an EstimationAssumptionsCollection which has EstimateAssumptions 
members. This is clean and uniform, but leads to extra levels of 
indirection and deeply nested XML (when resources are inlined in RDF/XML). 
ArthurRyman used a simplified approach in the Primer examples, i.e. a 
Project contains zero or more EstimationAssumptions members. This makes 
the XML more compact and readable.

SteveAbrams remarked that CM used explicit collections and that we should 
review the situation across the OSLC workgroups and define some best 
practices to achieve consistency across the spec.
[ACTION] SteveAbrams to add this topic to the OSLC Leads Meeting this 
Monday, 11:00AM EST. ArthurRyman to provide EMS examples. SteveAbrams to 
ask SteveSpeicher for CM examples.

Investment Risk
We reviewed the section on Investment Risk which introduced 
representations of probability distributions using TriangularDistribution 
and QuantileFunction resource types. LawrencePutnamJr agreed that 
QuantileFunction was a good way to express estimates. The ability to 
control the level of detail in a QuantileFunction by specifying the 
numberOfQuantiles property was consider to be very useful. Typically, the 
number of quantiles would be 10, i.e. deciles.

Getting Estimation Assumptions Automatically
AndyBerner posted comments expressing concern about the utility of trying 
to automate the collection of inputs to estimates. He had two concerns. 
First, the types of input vary between estimation tool vendors and models. 
Second, many assumptions are expressed in free form text and are attached 
to requirements and project plans, e.g. in a Project Vision document.

We agreed that although there were many differences between what vendors 
used as inputs, there were some widely used inputs, e.g. size, and it is 
useful to specify how to represent these in a machine-processible way.

We also agreed that the estimator would have access to other sources of 
text information. The estimation assumptions for a project could contain 
links to other documents, requirements, etc.

We discussed the workflow, i.e. how assumptions get created and used. The 
Primer describes the scenario where the assumptions are included in the 
the project proposal. However, it is equally possible that the estimator 
could define other assumptions for use in estimating alternate modes of 
running the project. The estimation tool could add these new assumptions 
to the project.

Next Steps
The description of the Initiating use case in the Primer is now complete. 
Next step is to add the Re-estimating use case to the Primer.

[ACTION] ArthurRyman to add the Re-estimating use case to the Primer.

2. Re-estimation use case [3] - Andy
Not covered.

3. Other Business - All

[1] http://open-services.net/bin/view/Main/MetricsMeetings
[2] http://open-services.net/bin/view/Main/MetricsEMS10Primer
[3] http://open-services.net/bin/view/Main/MetricsReEstimateUseCase

Arthur Ryman, IBM DE
Chief Architect, Rational Project and Portfolio Management
Office: 905-413-3077, Cell: 416-939-5063
Assistant: Nancy Barnes, 905-413-4182 
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