1
Tool for Process Structure Diagrams (TPSD).
2
-------------------------------------------
3
This tool is intended for process structure diagrams (PSDs) that are
4
used in the Jackson System Development method (JSD).
6
More about the drawing of PSDs can be found in chapter 5 of the
7
user's guide and more about the use of this notation technique can be
8
found in appendix A of the user's guide.
10
Diagram editing in general.
11
---------------------------
12
Diagrams that are made by a diagram editor are a special
13
kind of graph consisting of nodes and edges and with a certain
14
representation. In the representation of a graph, nodes and edges are
15
shown as shapes (boxes, lines, diamonds etc.).
17
Documents should satisfy certain constraints. Most constraints
18
are specific for the particular diagram technique supported by the
19
editor. In the editors there are three kinds of constraints:
21
1. Built-in constraints which are constraints which can never be
22
violated because there is no command in the user interface to achieve
25
2. Immediately enforced constraints: when you perform a command that
26
would violate a constraint that is immediately enforced, this command
27
is rejected immediately by the editor and a pop-up window with an error
30
3. Soft constraints which are constraints that can be violated.
31
Soft constraints are checked by the editor when the Check Document
32
from the Document menu is issued by you. Check Document displays a list
33
of error messages in a pop-up window. As opposed to the previous two
34
classes of constraints, you are responsible for correcting the diagram.