5.2 Examining the effects of a change

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Essentially, you must take CUST-NM and associate two subordinate fields with it, CUST-F-NM and CUST-L-NM. Let us look at one way in which you can use WSAA to help you complete this assignment. To do this, start with the results of the impact analysis your application development project manager created.

1. In your Web browser, open the Home page of WebSphere Studio Asset Analyzer.

2. Click the Explore tab to display the Explore MVS assets page.

3. Enter the search criterion, WSAA*, and click the Go button. The page is redisplayed with the search results.

4. Click the link (number) in the Results column next to Project under the Inventory heading. The Project summary page is displayed.

5. Click reanalyze next to WSAA Redbook project 1. The Project details: Analyze-change results page is displayed.

6. Click Show component details under the Actions heading. The page is redisplayed with additional information, as shown in Figure 5-1.

   
   Figure 5-1: Project details: Analyze-change results page with component details

You must scroll down the page to see this information.

Note 

Depending on the amount of information in your database, it may take a few moments before the page is redisplayed.

Clearly, this is a lot of information, and probably more than you really need to work with right now. We recommend that you print this page so that you have it as a reference point with which to continue working.

So, how do you isolate exactly what it is you need to change?

5.2.1 Determining the effect of a change

Why not start at the beginning? Go back to WSAA’s Home page, and perform a search for CUST-NM. Let’s see where that takes you.

1. On the Home page, enter the search criterion, CUST-NM, and click the Go button. The Explore MVS assets page is displayed with the search results, as shown in Figure 5-2. In this case, two Data element records were found.

   
   Figure 5-2: Explore MVS assets page with search results for CUST-NM

2. Click the link (number) in the Results column next to Data element under the Data heading. The Data element summary page is displayed, as shown in Figure 5-3.

   
   Figure 5-3: Data element summary page with search results for CUST-NM

   You can see the data element name, the two programs in which it is used and those programs’ source locations. WSAA presents you with information about the field’s definition and lets you know that this data element is found in a copybook.

   Note 

   Normally, we would instruct you to select both items and click the Analyze-change button. However, because the CICS analysis scanner does not work on our system, the resulting output has no values at all.

   We hope that you have the patience to wait while we show you the same information in a less direct manner. One good thing about WSAA is that there are often a few ways in which to obtain and present specific information.

3. Click CUST-NM for the batch program, TRADERB. The Data element details page is displayed.

   1. First, we want to see what the field looks like. Click View source under the Actions heading. The View Data Element use in Program page is displayed in a new browser window, as shown in Figure 5-4.

      
      Figure 5-4: View Data Element use in Program page for CUST-NM

   WSAA displays the contents of the copybook for you. The field, CUST-NM, is located in DNET998.DEMOS.PDPAK.COPYLIB(CUSTFILE). WSAA has even highlighted the significant aspects of this data element for you.

   Note 

   In each of the three categories — Data definition, Data reference, and Data modification — the line numbers are links to the specific location within the displayed code.

   Here, you can see exactly how this field is actually defined. In this example, it is a single field of 60 bytes. Take note that it is part of the key of the Customer file. You must exercise some caution when you split the field into two parts.

   Click x to close this window.

   1. Scroll down the Data element details page to find additional, pertinent information as shown in Figure 5-5.

      
      Figure 5-5: Data element details page of CUST-NM for batch program TRADERB

   Here you can see that the copybook, CUSTFILE, is also used in the online program MYTRADS — which corroborates the information you saw on the Data element summary page.

   WSAA then presents additional information about this field. You can see the relationship with other data elements in the TRADERB program. There are data elements that:

   • Are modified by this one

   • That modify this one

   • Reference this one

     Note 

     If you were conscientious (and thorough) enough, you could scan through the bottom of the TRADERB compile listing to find this information. However, all you would have at that point would be the line numbers indicating which lines in the listing were significant. You would still need to scroll back up to the expanded source to find each of the instances where the field was modified.

   WSAA has already done all of that work for you (without actually compiling the program) and has concentrated the information on one page so that you can drill down to quickly and easily obtain the information you need.

   Let us look at the first data element that references CUST-NM, TR-CUSTOMER-NAME.

4. Click DNET998.DEMOS.PDPACK.SOURCE(TRADERB) line 542 in the Source location column. The source code listing is displayed in a new browser window, as shown in Figure 5-6.

   
   Figure 5-6: TRADERB source code showing a reference to CUST-NM

   Here, you can clearly see that TR-CUSTOMER-NAME is moved to CUST-NM.

   Click x to close this window.

   Now, let us look at TR-CUSTOMER-NAME to see how it is defined.

5. Click the first instance of TR-CUSTOMER-NAME in the Data element reference column. Just as you saw for CUST-NM, the Data element details page is displayed.

6. Click View source under the Actions heading. The contents of the copybook are displayed in a new browser window, as shown in Figure 5-7.

   
   Figure 5-7: TRANFILE copybook showing the definition of TR-CUSTOMER-NAME

But wait, what’s this? The field, TR-CUSTOMER-NAME, is defined in the copybook TRANFILE as a 30-byte field! Obviously, you have an issue to report to your application development project manager.

Now, after some discussion, in addition to creating a first and last name field for CUST-NM, you also need to expand the size of TR-CUSTOMER-NAME, (as well as the file it represents).

Note 

We are well aware that you could have made this discovery if you were using your existing methods of maintaining program source code. WSAA just brings all of the potentially hidden material to the foreground.

That concludes the research for the fields associated with CUST-NM.

5.2.2 Results of your exploration

You have explored a variety of aspects of WSAA in your search to segment the CUST-NM field. What tasks do you see that will require you to make changes?

• Update the copybook, CUSTFILE, with the new segments of CUST-F-NM and CUST-L-NM.

• Update the copybook, TRANFILE, to expand the TR-CUSTOMER-NAME field.

• Recompile the two programs that use the copybooks:

  • TRADERB

  • MYTRADS

The latter may have additional considerations, but that work is beyond the scope of this chapter.

Oh, and what about the JCL that references these application data files? Well, those are actually displayed in the detailed information your project manager originally generated for you; see Figure 5-1 on page 141. We will leave that for you to explore on your own!

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