Reading:
Specifying System Requirements
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Field name | Field name | Field name | Field name |
Client ID | School number | Discharge status | Relation |
Program | School type | Admission time | Relation |
Site | involved | Admission type | Ref required |
Program group | DSS involved | Referred to | Ref required |
Admission date | Custodian | Hospitalization | Co-pay |
Discharge date | Homeless | Plan code | Co-pay |
Primary staff /team | Foster care | Pay source | Update date |
Presenting problem | Foster care placement | Pay source | Entry date |
Referred from | Furlough | Payer 1 | User name |
Target population | Crisis bed requested | Payer 2 | |
Axis I | Last ITP date | Insurance type 1 | |
Axis I | Treatment plan date | Insurance type 2 | |
Axis II | Dr order date | Policy number 1 | |
Axis II | Last assessment date | Policy number 2 | |
Any Axis III | Discharge type | Effective 1 | |
Axis IV | Hospital discharge date | Effective 2 | |
Axis V / GAF score | Final agreement date | Expiration 1 | |
Legal problem | First contact | Expiration 2 | |
Alcohol problem | Referral date | Policy holder 1 | |
Drug problem | Discharge referral | Policy holder 2 | |
Table 1: List of Fields in One of the Tables in the Existing Database |
The tables in the existing database kept multiple pieces of unrelated information in the same place. For example, it put name, address, demographic, arrest history and medical history in the same table. Clients of the court changed their address frequently. Every time the address changed the entire record needed to be changed. Every time the client was arrested, another entire record needed to be put in. The value of examining existing databases is that they suggest potential fields and may explain why existing databases are frustrating. In this manner, future design can avoid past errors.
Second, it is important to trace the paper flow. Many organizations have paper forms that document decisions made by them. These paper flows are an important source of ideas regarding what information might be kept in the new database. For example in the mental health court example, the following paper forms were used:
The forms pointed to several decisions that the organization needed to make. The form on pre-admission screening and the admission forms pointed to the decision about diverting a defendant from usual jail and court processes to special processes set up for mentally ill patients. The demographic and the monitoring form pointed to the information needed for deciding on the effectiveness of the diversion process. The discharge form was used to decide about court staff's assigned work load. These forms point to what data might be needed for which decisions.
One obvious way for assessing information needs is to ask organizational leaders what should be included in the database. Information users have a great deal of problems in articulating their own needs. When asked, they often produce a long wish list of data that those not correspond to their true needs. They include items that they will not use and do not mention items that they will need. Organizational leaders fall victim to their own cognitive limitations. When interviewed, they have to remember how key information was missing in the past decisions. This is very unpleasant. No one wants to remember failures or episodes in which their needs were not satisfied. Unpleasant events are often forgotten, especially when you, yourself, are in charge. Interviewing organizational leaders about failures of their organizations is akin to asking them to fess up to their own mistakes. It is an unpleasant task that many rather forget. Furthermore, many decision makers do not realize how their own needs change over time and how these needs are affected by external events. They are so engaged in everyday work that they have not had an opportunity to envision a different arrangement. Many are not aware of new technological possibilities and keep projecting future needs based on their existing expectations. In short, many fail to imagine a new future. To overcome these limitations, it is important to put organizational leaders in a new mind set. The analyst can do so by first ask what are future decisions that the database should address and then assess information needs within these decisions. Clearly, information needs change over time and by repeating what has been to date, organizations may put themselves in a disadvantage. This may be acceptable in a stable environment, but not in a dynamic one. A focus on future decisions transcends this pitfall and provides a context for the value of various pieces of information.
Information collected in a databases data that have been consistently relevant to a particular decision. This is how an analyst can decide to collect or to ignore a datum. If in a given decision, there is no requirement to examine a price of data before making the decision then the database should not contain it. Only that portion of the information which we will use need to be stored and retrieved at a later time. Other information may reside elsewhere in the system, may be relevant to decisions not addressed by the database or may be handled in a different way at the time of decision making. A focus on decisions makes sure that long wish lists of information items that are never used do not clutter the system and drawn out the opportunity for collecting what really would influence actors.
An analyst has no choice but to select a few fields and focus on them rather than all possible fields of information. If you look around you, you'll see many objects. Each one of those objects has potentially hundreds, or even thousands characteristics. For example the monitor in your computer has a model number, a type, a model name, a type of display, a color or colors, a height, a width, a depth. Is that all? Well, probably not. It depends on how detailed you want to be. You could also describe the lettering that the monitor may have, where that lettering is located, what color is the lettering in. Have we exhausted all the things we can say about the monitor? Hardly. We could take a magnifying glass and look for scratches and indentations on the frame of the screen, we could describe what the chemical composition of each one of the parts of the screen is, and so on and so forth. Clearly, objects are awfully rich in terms of their characteristics. An analyst must figure out what is pertinent for the database purposes and what is not. If I am a clinician I will be interested in those characteristics of a patient that are pertinent to my decisions about his health. If I am a banker, I will be interested in the financial characteristics of my client. So for every domain there are objects that are pertinent, and for each one of those pertinent objects there are characteristics that support the purpose of our database. Everything else is irrelevant and we must filter that out when considering how to build an information model. Since data become informative in the context of particular decisions, then the simplest step is to evaluate the relevance of a datum in the context of a decision that needs to be addressed by the actors.
By focusing on future decisions, the databases designer anticipates various roles the information system might play. For example, in the mental health court project, we were given a tour of the court. While at the court, it became clear that many defendants come to the court without their data being available. A significant component of the time is spent in the court sorting out who knows what about the defendant. In one case, the FAST social worker reported that they had not been able to get a response from the health care provider regarding defendant's competency examination. The probation officer reported that he has not been able to locate the client in the community. The defense attorney reported that he had not met with the client yet to see how the examination went. All along the judge was left waiting for information. Eventually, the judged called the doctor involved and talked to him on the phone who collaborated the client that that she had gone to the clinic, had been examined but did not want to take the medications prescribed. It was clear from this case that an exchange of information between the FAST database and the clinic would solve the problem. Health care providers, for example those in the Veterans Administration, were reluctant to provide the care because of extensive court required paperwork. With the automated exchange between the clinic database, the court will be well informed and the clinicians would not need to file additional forms. But the FAST social workers seemed unaware that the Veterans Administration had a great electronic medical record system and that it was possible to create the electronic link to it. When the option was described to them, they were not sure that such links can be made. So asking the organization employees about what they need may not be enough. Sometimes, specially when it comes to automation of tasks previously done manually, designers of new databases need to lead the effort.
A A similar example occurred when we noticed that FAST social workers, treatment programs and court staff have a difficult time identifying cases. Many patients give different names at time of arrest and in clinics -- creating a havoc in matching the information to the right person. One way to overcome this is to include an image of the person in the database. When employees were asked what they want in their database, none mentioned an image of the client. But when work processes were examined and improvements solicited, many pointed out that some clients do not have identification on them and use different aliases and names. When we suggest that this could be done, they were very enthusiastic. The point is that designers cannot completely rely on organizational leaders on what should be included in the design. Part of their task to push for change in business processes and information that should be collected in the database but that are not mentioned by organizational leaders.
To be effective, an analyst must ask both organizational leaders and outside experts to identify the work processes that must be improved. By relying on a group rather than an individual, the analyst minimizes the cognitive and behavioral limitations of having a single person define information needs. The information system that emerges may not fit the idiosyncratic needs of a particular individual but it transcends people who come and go and serves the organization as a whole -- no matter who is in charge and for how long. By adding external experts to the membership of the group, the analyst emphasizes what people in the organization want and what people outside think they may need. It brings an outside point of view and breaks up the set ways of doing things.
In the mental health court example, we had heard of a Federal system for probation officers. In some sense the FAST social workers were doing activities similar to the Federal probation officers: they were tasked with monitoring adherence with the court ordered actions in the community. To gain a better understanding of what the FAST database needed to look like, we examined the Federal system. p>
Scenarios are snapshots of a story you are telling about how a database will be used. You should make different scenarios about each decision. In the scenario you should talk about how the actors will interact with the database to make a specific decision. Here is an example scenario on admission to the FAST program:
Scenario short
name: Admission Decision affected by this scenario: Admission to FAST program Actors: Jane, Connie, and Sheila Description: Sheila enters the demographic and arrest ˜ records, Connie and Jane review the patient and enter presumed diagnosis and their recommendation for admission to FAST program. ˜ Through out the process the database maintains the information and ˜ assists in the communication between people involved. |
Additional scenarios can be written about how the database ˜ helps in other decisions, for example the decision about what ˜ treatment should the patient participate in. In the end when you have ˜ developed a number of scenarios, you have a way of telling a complete story ˜ about what the database will do and what decision it will have an impact on.
Within the targeted work process, develop use cases, i.e. describe how information systems will be used to accomplish the work in new and better ways. The use case method was pioneered by Ivar Jacobson, one of the three creators of the Unified Modeling Language, an important language in designing databases. The purpose of a use case is to describe the behavior of the system from the point of view of the user interacting with that system. By stating how the system reacts, that is, what it does, when the user gets in contact with the system it is possible to gather the kind of information that will be needed to support these system actions.
For example, in the mental health court system a receptionist was asked to collect information from the Federal and State databases regarding a client's "wrap" sheet. This information was then put into the computer to document the case for a client being considered for the FAST program. A form was provided to the receptionist asking her about the client's demographic and arrest information. This form was then communicated to the FAST social workers who established the client's presumed diagnosis and eligibility for the FAST program.p>
In Unified Modeling Language one uses a series of icons to graphically depict a use case diagram. The actor is always external to the system and is normally represented as a stick figure with a label underneath it that identifies what kind of actor it is. Note that the term "actor" is not meant to be restricted to human users alone. Any object in the business domain that interacts with the system can be considered an actor. For example, another system can be an actor, if it sends or receives information from our database.
The database or system is normally shown as a rectangle, and it also has a label that identifies it within the business domain. Inside the rectangle that represents the system there are ovals which correspond to the actual use cases. Each oval has a label which can be placed either inside the oval or immediately below it. The label is a short-hand for a given functionality of the system. The recommended practice is to use succinct phrases, for example verb-noun pairs, for the label of each use case to convey what the system does.
LaLastly, straight lines are used to connect actors to the various use cases of the system. When an actor is connected to a use case in a system it indicates that the actor interacts in some fashion with that functionality of the system. Needless to say, the bulk of the description for what that interaction consists of is not shown in the diagram itself, but is captured in a descriptive narrative. The diagram is simply a very high level depiction of the actors and their connectivity to the system. The tools for Uniform Modeling Language normally offer data entry forms where this information can be documented. In absence of case tools one can use a word processing software to document a use case. By following this discipline we can get a handle on what type of information is required by the system in order to operate correctly.
The process of building use cases focuses on the message flows exchanged between the actors and the system. There are four main categories of actors which can be documented in a use case Diagram. First we have (a) the principal actors, which generally will be humans interacting with the system and its various functionalities, next are (b) the secondary actors, which normally are individuals performing administrative or maintenance functions with respect to the system. The third category of actors is (c) the external hardware. This includes those peripheral devices that enable the input / output functions for the system. For example, the terminals through which a human user can log in, the printer devices that generate hard copy reports, etc. Lastly, there are the (d) external systems which interact with our system. In a complex application our system may be linked to a local network which provides the connectivity to the Internet, or to the e-mail server within the organization.
Each of these potential actors may send to and receive information from the system, and each of these flows may depend on the sequence of interactions between the user and the system. A given sequence of interactions is normally bundled into what is called a scenario. A patient accessing an on-line medical system may participate in multiple scenarios depending on what sequence of interactions he engages in. In one scenario, the patient may be simply searching for answers to a query posted previously. In another scenario, the patient may be reporting his health status after having followed the medical treatment recommended by his physician of record. Different use cases can then be documented for each scenario. All scenarios must be linked to decisions. In the first scenario, the patient is deciding whether to come in for a visit. In the second scenario, the provider is deciding if the patient needs to return for a follow-up visit.p>
Table 3: Example of use cases with two actors<
The following shows an example of a use case Diagram using Uniform Modeling Language notations. The system we are dealing with is the mental health court system. A receptionist is shown with access to the registration use case. The FAST social workers are shown interacting with module for presumed diagnosis and monitoring. We have at least two actors, namely, the receptionist and the FAST social worker. The functionality of the system for this scenario is shown in the three use cases shown in the diagram, namely, the Registration Management, the Presumed Diagnosis and the Monitoring component. The diagram shows that the FAST social worker interacts with all three of the system functionalities, whereas the receptionist is focused on the registration component. More careful examination of the system revealed several flaws in the use case scenarios. First, one of the social worker was disabled and could not interact with the computer directly. This necessitated the need to send information that needed to be put into the computer back to the receptionist. Therefore, in reality and at least for one social worker, the receptionist did all of the interaction with the system.
But pictures do not tell the entire story and we need to have the details captured in the use case document. It is generally recommended that a use case document should contain:
Of course other information can also be kept about each use case:
There is no canonical form that one must always adhere to for documenting a use case. Here is an alternate way of documenting the Registration Management use case.
Documenting Use Caseuse case: REGISTRATION MANAGEMENT
Overview
Primary Actor
Secondary Actor
Starting Point
Ending Point
Information Exchanges
Measurable Results |
Figure 4: Alternate Documentation of a use case
At the end of specifying system requirements you should have a list of fields that correspond to various uses of the database. The more details are specified in a Use Case the easier it is to extract the type of information that the system will require, and, consequently, the easier it will be to generate the database fields. The use cases gives us the entry point into the actual process of developing the information model for the target database. It helps us specify specific fields needed.
In assigning field names Hernandez (pages 209-211) suggests you follow these rules:
We also add the following additional criteria:
End the process with a thorough and careful documentation. For each of the fields, provide the name of the field, a short definition, any restriction that pertains to the values the field and the type of values expected. Types of data allowed depend on the manufacturer of the database software you are using. Some common types are:
Careful documentation and frequent sharing of the documentation with organizational members can help the design of databases.
Another example of how process improve derives the specification of system requirements occurred when we needed to design a new electronic health record for primary care. We were asked to design an information system for an HMO that would radically improve the work processes. In this HMO, the central business justification for the Electronic Health Record was to reduce visits while maintaining quality of services. This was an unusual situation in the sense that both patients and providers had access to email and Internet. The idea was to take advantage of the availability of the improved communication channels and design work processes that reduced unnecessary visits, saved the patient's time and the HMO's resources. The assumption was that informed consumers would be willing to take care of their own health if their clinicians were readily available to them and willing to work with them remotely. The electronic health record was expected to support these revised work processes. The design of the Electronic Health Record had to assume process changes that were planned and information requirements when these new process changes were put in place.
The content of primary care can be broken into 150 different diagnoses, typically seen at any office. Sixty clusters of disease explain 80% of visits. Each cluster is a use case, a scenario, under which we can examine impact of EHR. In each cluster, ask internal & external experts how EHR will reduce visits. We started from the most common reason for the visit, created a use case for it, and showed how the new information system would change the work process. Then we went to the next reason for visit and repeated the same procedures until use cases for majority of visits were determined. We analyzed the content of these uses cases to establish what new information would be needed and at what point in time.
The most common reason for a visit to a primary care setting is "General Medical Examination (well visit)." The new process assumed that patients will visit lab before coming to scheduled appointments. They would complete an online risk assessment immediately following making an appointment. Computer will provide feedback. Computer will guide patient in doing self examination, even prior to visit. The computer will help patients plan questions they want to ask during the visit. All of this meant that an online risk assessment, online guides for self examination, and online planning a visit had to be in place. It meant that data regarding patients' progress in accomplishing these tasks had to be recorded. These data items were added to the system requirements. The clinicians and external experts anticipated that given the new process for well visit may drop the time from 1 hour to ½ hour in 70% of the cases. This meant that the system was being designed to accomplish the goal that was set for it: reduce cost and improve quality.
The next most common reason for a visit to a primary care setting is "Acute Upper Respiratory Infection Cluster." The new process assumed that patients would contact clinicians by phone or email. Clinicians will review the symptoms and asks the patients in some cases to delay visits. They would ask the patient come in next day if symptoms got worst. In addition, the process assumed that the computer would need to follow up with the patient to see if symptoms have gotten worse. The clinicians and experts assumed that these new procedures will reduce visits in 60% of cases, where patient gets better after waiting. The new system also assumed the availability of a great deal of information from patient's early symptoms, patient's later symptoms, ease of access (preferred mode and time), patient's choice to delay visit, and follow up resutls. These information items were added to the system requirements.
The third most common reason for visit to primary care is "Pre and Postnatal Care." Here again a new process is imagined. Some prenatal in some patients can be avoided for patients with positive laboratory tests. The same for some post-partum visits, if the system triages depressed patients directly to specialists and by passes the primary care visit. The experts anticipated that in this disease cluster, very few patients could benefit from reduced visits. They expected a 10% reduction in visits. The choice of whether a visit can be avoided seem to depend on the confidence that the primary care provider had in the patient's ability to understand the lab tests and follow through with subsequent visits.
The process was continued until the majority of reasons for visits were analyzed and a use case for each type of visits was developed. The information requirement was then derived from these uses cases. This example shows how information needs are derived from upcoming decisions within new work processes. Of course, some people may not agree that the proposed new processes were reasonable. Everyone will agree that, if we want to get to new work processes, we must plan for the information needs of these new work processes.
This page was organized by
Farrokh Alemi, Ph.D. Last date of revisions was on