AN INTERACTIVE GRAPHICS EDITOR WITH INTEGRATED DATA DICTIONARY FOR IDEFo STRUCTURED ANALYSIS DIAGRAMS Thomas C. Hartrum, Ted D. Connally, and Steven E. Johnson Department of Electrical and Computer Engineering School of Engineering Air Force Institute of Technology Wright-Patterson AFB, Dayton, Ohio, 45433 supports a classical process-oriented lifecycle based on the Abstract ideas in Dod Standard 2167. A standard “waterfall” model Most of the commercially available structured analysis tools are is followed, consisting of a Requirements Analysis phase, a based on data flow diagrams. However, many Government agencies, from the Air Force Materials Laboratory to the Strategic Defense Ini- Design phase, an Implementation & Testing phase, and a tiative Office depend on IDEFo diagrams, a derivative of SofTech’s Maintenance phase. Each phase is supported by database Structured Analysis and Design Technique (SADT’). This paper de- consisting of specific data dictionary entries. scribes SAlool, a graphics IDEFo editor for a SUN workstation. This paper describes a graphics tool developed to sup- An extension of the original IDEFo definition is a data dictio- nary. Entries are defined for both activities and data items, and port the Requirements Analysis phase and the integration mapped into a relational database management system (DBMS). A of that tool with a centralized relational database manage- data manager handles checking data out of the centralized DBMS in ment system. Some results of analysis of user satisfaction a format useable by the graphics editor and updating the appropriate with this tool are also presented. This paper describes relations when the data is checked back in. The data manager was developed in a generic format to support other software development the integration of these two techniques into a computer tools. automated tool SAtool for the purpose of improving the The editor and data manager, as part of the Air Force Institute software requirements analyst’s productivity. This pro- of Technology’s System 690 software development system, were used ductivity increase is possible for two significant reasons. in the development of a distributed mail system. User acceptance of the tool was measured through the use of a user survey. Results of First, several pieces of information are needed for both an this survey, as well as a description of the editor and data manager, SA diagram and the corresponding data dictionary entries. are presented in the paper. The integration of the two methods eliminates significant duplication of effort to enter the information. Second, the analyst is freed from much of the effort needed to create the diagram manually by using a tool tailored for this specific 1 Introduction purpose. SAtoolexecutes on a SUN workstation and trans- fers data dictionary information over a TCP/IP local area System 690 is the name given to the software development network (LAN) and through a data manager to a central environment under development at the Air Force Institute relational database management system on a Unix-based of Technology’s Department of Electrical and Computer Vax computer. Engineering. The goal of System 690 is to provide an integrated system in which a designer could sit down at 2 Requirements Analysis Method- a workstation, download the necessary data from a cen- tral database, work on a portion of the design, and when ology finished, upload the modified data back to the database. This data, stored in a comprehensive,centralized database, The requirements analysis phase of the software life cycle would support a system which could share data between is an important one. System 690 has established an anal- tools and provide the means to document a software project ysis methodology for this phase of the software life cycle throughout its entire life cycle. that consists of using structured analysis (SA) d’iagrams System 690 is based on a set of integrated workstation and a data dictionary. This section describes each of the tools and a central database to support a specific design components. methodology. In its current implementation, System 690 2.1 ’SA Diagrams ‘SADT is a registered trademark of SoUech, Inc The SA diagrams use a graphical language that is de- This work sponsored by SDI0 rived from the Structured Analysis and Design Technique 765 U.S. Government work not protected by U.S. copyright. AUTHOR' lEdM 4 ~O~lE.BI/BBIEB~R€~DERI I I (SADT) (SADT is a trademark of SofTech, Inc.), and are PROJECT: ECS (REV:I.I DATE accompanied by facing page text to assist in the under- optlo" standing of the diagram. Rectangular boxes and arrows are the primary graphical constructs used in an SADT di- agram. The boxes represent the decomposition of the func- tions .of the system being analyzed. The arrows are used to describe how the boxes interface between each other on the diagram. The graphical language consists of English text to label the diagram and 40 graphical constructs to describe relationships [I]. SofTech proposed that the SADT methodology could be applied to many types of problems in addition to soft- ware requirements analysis [2]. The U.S. Air Force Pro- gram for Integrated Computer Aided Manufacturing (ICAM) adopted a version of SADT from SofI'ech and called it ICAM Definition Method Zero or IDEFO. Now the Air Figure 1: Example IDEFo Diagram Force uses this similarly structured methodology to im- prove the communication of people who use computers to increase manufacturing productivity. System 690 uses the IDEFo syntax to support the re- quirements analysis phase of the software development life- cycle. A example of an IDEF, diagram as produced by NAME: mess-parts SAtoolis shown in Figure 1. PROJECT: NETOS-IS0 TYPE: PARAMETER 2.2 Data Dictionary DESCRIPTION: Decomposed message parameters. DATA TYPE: C structure or PASCAL record. The purpose of a data dictionary is to manage and docu- MIN VALUE None ment data. According to Lefkovits (Lefkovits, 1977), using MAX VALUE: None data dictionaries provides many benefits including: reduc- RANGE OF VALUES: None tion of administrative effort, reduction of data redundancy, VALUES: None and reduction of system development costs. Regarding PART OF: None software requirements analysis, Leong-Hong and Plagman COMPOSITION: suggested that data dictionaries are an excellent vehicle SRC for maintaining documentation. Furthermore, they rec- DST ommended that the data dictionary systeiii for producing QTY documentation be automated to reduce the monotony of Buffer the task. [3]. ALIAS: Message Parts In System 690, a data dictionary is established for WHERE USED: Passed to Flush Buffer. the Requirements Analysis, Design, and Implementation COMMENT: Part of existing library. phases of the software life cycle. Each of these phases con- REFERENCE: MSG-PARTS sists of a set of action entities and a set of object entities REFERENCE TYPE: SADT for a total of six types of data dictionary entries. Figure 2 VERSION: 1.2 shows a sample data dictionary entry. VERSION CHANGES: Component USE added The data dictionary entries, as can be seen from Fig- DATE: 11/05/85 ure 2, are designed to be readable by human analysts. The AUTHOR. T. C. Hartrum corresponding relational database consists of a number of CALLING PROCESS: Process Message third-normal form relations. (Figure 3 shows the schema PROCESS CALLED: DecomposeMessage for the design phase object entity). The data dictionary DIRECTION: up database contains the schema for all six data dictionary en- 1/0 PARAMETER NAME: partslist tries, and is implemented using the Ingres relational DBMS under the Unix operating system on a VAX 111785. Figure 2: Sample Design Phase Object Entity Dictionary Entry [4] 744 parameter 2. Break the input process into parts to achieve “psy- project c12 chological closure.” paname c25 3. Provide positive feedback to the user. datatype c25 papassed low c15 project c12 4. Minimize memorization required by the user. hi c15 paname c25 span c6 0 prcalling c25 5. Provide a visually pleasing display on the screen. prcalled c25 status cl 6. Minimize the response time of the tool. direction c4 padesc iopaname c25 Finally, part of the tool’s function was to provide hard- project cl 2 copy outputs of the various products maintained by the paname c25 pavalueset tool. Therefore, it was required that the tool implement a line i2 project c12 means to produce the iIDEFo diagram, the accompany- description c60 paname c25 ing facing page text, and the data dictionaries generated value c15 by the tool. paalias pahierarchy project c12 3.2 Description of the Tool paname c25 project c12 aliasname c25 hipaname c25 SAtool was designed to run of SUN workstations due to comment c60 lopaname c25 their availability. Each SUN has a large display moni- whereused c25 tor to accommodate an uncluttered user interface, and a paref mouse input device for manipulating the graphical con- pahistory project c12 structs of the IDEFo diagram. In addition, all the SUN project c12 paname c25 workstations are tied to the AFIT computer network, im- paname c25 reference c6G portant for transporting the data dictionary information version c10 reftype c25 to the central computer. Based on the availability of the date c8 SunView package and the desire to reuse certain software author c20 modules from the prototype, it was decided to proceed comment c60 with the SunView package. The tool was implemented in C because SunView supports this language. Figure 3: Database Schema for the Design Phase Object The design of an acceptable human/computer interface Entity [5] was a primary task in this effort. The screen layout con- sists of five areas or windows as shown in Figure 4. 3 SAtooZ, an Interactive Graphics Editor 3.1 Requirements Definition Requirements for this tool were based on previous research at AFIT. A prototype tool to integrate SA diagrams and data dictionaries was built at AFIT in 1986.