Enclosed is a paper that advocates an additional set of activities that the authors believe that the OGSA working groups should engage in. Broadly speaking, the OGSA and related working groups are already doing a bunch of important things: * There is broad exploration of the big picture, including enumeration of use cases, taxonomy of areas, identification of research issues, etc. * There is work going on in each of the horizontal areas that have been identified, such as EMS, data services, etc. * There is working going around individual specifications, such as BES, JSDL, etc. Given that individual specifications are beginning to come to fruition, the authors believe it is time to also start defining "vertical profiles" that precisely describe how groups of individual specifications should be employed to implement specific use cases in an interoperable manner. The authors also believe that the process of defining these profiles offers an opportunity to "close the design loop" by relating the various on-going protocol and standards efforts back to the use cases in a very concrete manner. This provides an end-to-end setting in which to identify holes and issues that might require additional protocols and/or (incremental) changes to existing protocols. The paper introduces both the general notion of doing focused vertical "design efforts" and then focuses on a specific vertical design effort, namely a minimal HPC design. The paper derives a specific HPC design in a "first principles" manner since the authors believe that this increases the chances of identifying issues. As a consequence, existing specifications and the activities of existing working groups are not mentioned and this paper is not an attempt to actually define a specifications profile. Also, the absence of references to existing work is not meant to imply that such work is in any way irrelevant or inappropriate. The paper should be viewed as a first abstract attempt to propose a new kind of activity within OGSA. The expectation is that future open discussions and publications will explore the concrete details of such a proposal. This paper was recently sent to a few key individuals in order to get feedback from them before submitting it to the wider GGF community. Unfortunately that process took longer than intended and some members of the community may have already seen a copy of the paper without knowing the context within it was written. This email should hopefully dispel any misconceptions that may have occurred. For those people who will be around on for the F2F meetings on Friday, Marvin Theimer will be giving a talk on the contents of this paper at a time and place to be announced. Marvin Theimer, Savas Parastatidis, Tony Hey, Marty Humphrey, Geoffrey Fox