Next: EPOS architecture
Similarly to what has been done with the introduction of software
life cycle, it is possible to identify the phases which characterize
the development of a software process: from its
creation to its enactment (and, possibly, maintainance).
Such phases represent ``the process which manages process
models'', i.e. the Meta-Process
The following list represents the meta-activities supported
(or, at least, identified) by EPOS, even though assuming it valid for
the PM discipline in general is probably accurate (which does not
imply that every PSE allows the distinction or the formalization of
all of them). This list was taken from [CFF93] :
- PM0. Provide a Process Support Environment (PSE).
It must contain a PM methodology,
a Process Modelling Language (PML),
libraries of reusable process models expressed in the PML, and
process tools for acquisition, modelling, analysis, evolution,
execution, monitoring etc. of process models.
PM0 consists of SPELL, EPOSDB, and EPOS process tools mentioned below.
- PM1. Elicit requirements for an informal process model.
No computerized support is offered for PM1.
- PM2. Analyze and Design a model.
The Design of the process model is facilitated by the
Schema Manager (meta-)tool. It enables the manipulation of
the representations of the process elements, according to
the EPOS paradigm. This meta-activity is often carried out
by browsing, editing and modifying a library of reusable
model fragments (types in the case of EPOS).
- PM3. Implement/Instantiate the model.
The template process model is instantiated to conform to the
real process to support. The instantiation is determined by
the actual products, tools, schedules and human resources.
PM3 is supported by the following (meta-)tools:
Furthermore, there are some extractor and editor tools to handle
the product models.
- Planner: it is invoked everytime a task must be
decomposed in (sub)activities (in short: it builds the
- Cooperation Manager: it sets up and maintains communication
protocols between each pair of isolated working
environments (transactions) with overlapping scopes.
- Workspace Manager: it manages Workspaces.
A subset of a bound sub-DB, a configuration,
can be checked-out into and checked-in
from ``DB-external'' and possibly distributed
workspaces with special data representations.
This allows easy access by conventional tools, and corresponds to
the classic copy-modify-merge paradigm.
stand in a one-to-one relationship with transactions
and provide the latter with mechanisms
which avoid unjustified access to data outside of their
- PM4. Execute the model.
This phase consisists of the guided or enforced use the available
production tools for
accomplishing the goal of the process (e.g. compilers and
PM4 interprets the model (through SPELL
interpreter and Execution Manager).
- PM5. Monitor and asses external process performance.
with feedbacks to PM0--PM4.
This goes in parallel with PM4 on execution.
EPOS has no other tool support here than the above PM2--PM4 tools.
In addition comes human observation and intervention.
Even though this presentation provides the reader with a
``waterfall'' vision of the Meta-Process, such assumption is not
Next: EPOS architecture
Mon Feb 20 21:59:27 MET 1995