Solutions to Industrial Engineering problems using integrated software environments

The development of word processing systems and the spreadsheet environment marked the beginning of the professional computing movement. For the first time, programs were available that were both highly functional and highly usable, even by non-computer people. The next group of “hot” programs in the business market were “integrated” packages providing a combination of word processing, spreadsheet, database, graphics, and telecommunications. Unfortunately, these integrated packages have not displaced such single purpose programs as Lotus 1-2-3, dBase and WordPerfect as the dominant forces in desktop computing. Integrated packages are generally perceived as complex, cumbersome, and difficult to master. An important point to note, however, is that high proficiency is not necessary; successful users of commercial software seldom know or use more that 40% of a programs functionality.

This paper addresses the use of integrated software packages to solve Industrial Engineering problems. More specifically, examples are presented demonstrating the use of Ashton Tate's Framework II to solve production and operations management problems. Sample applications include forecasting, after tax economic analysis, and data storage and retrieval, demonstrating the advantages of linking word processing, spreadsheets, and databases.     

Measuring the learnability of spreadsheets in inexperienced users and those with previous spreadsheet experience

The issues of 'usability' and 'learnability' are assuming an increasingly important role for both the designers of software and their prospective customers. Objective measures of the interaction between system and user are important for the development of software that is both easy to learn and pleasurable to use. In this study we apply a set of five measures to evaluate users' interactions with spreadsheet software, and to compare two spreadsheet packages. We tested 16 people with no previous experience of spreadsheets and 16 with experience of spreadsheets generally though not of the spreadsheet we gave them. Half were allocated to learn Excel and half to learn Wingz, running on Apple Macintosh computers. A standard task was constructed to assess understanding of the basic concepts involved in the use of • spreadsheets. Users' previous experience of spreadsheet use was the most salient factor in the scores achieved on the task. The brand of spreadsheet had no significant effect on task performance. Implications for designers of software and users of spreadsheet packages are discussed.     

Analysis and improvement of business process models using spreadsheets

Software in general is thoroughly analyzed before it is released to its users. Business processes often are not – at least not as thoroughly as it could be – before they are released to their users, e.g., employees or software agents. This paper ascribes this practice to the lack of suitable instruments for business process analysts, who design the processes, and aims to provide them with the necessary instruments to allow them to also analyze their processes. We use the spreadsheet paradigm to represent business process analysis tasks, such as writing metrics and assertions, running performance analysis and verification tasks, and reporting on the outcomes, and implement a spreadsheet-based tool for business process analysis. The results of two independent user studies demonstrate the viability of the approach.     

Exception handling in the spreadsheet paradigm

Exception handling is widely regarded as a necessity in programming languages today and almost every programming language currently used for professional software development supports some form of it. However, spreadsheet systems, which may be the most widely used type of “programming language” today in terms of number of users using it to create “programs” (spreadsheets), have traditionally had only extremely limited support for exception handling. Spreadsheet system users range from end users to professional programmers and this wide range suggests that an approach to exception handling for spreadsheet systems needs to be compatible with the equational reasoning model of spreadsheet formulas, yet feature expressive power comparable to that found in other programming languages. We present an approach to exception handling for spreadsheet system users that is aimed at this goal. Some of the features of the approach are new; others are not new, but their effects on the programming language properties of spreadsheet systems have not been discussed before in the literature. We explore these properties, offer our solutions to problems that arise with these properties, and compare the functionality of the approach with that of exception handling approaches in other languages     

Review of generic software for environmental engineering applications

Generic software such as spreadsheet and data base programs provide utilities that can be used to construct routines for various applications. The specific used is determined by the user. Generic software allows interactive programming and data manipulation. These programs have dramatically changed the everyday use of microcomputers by creating an easy and flexible interace ofr inexperienced computer users to create their own user defined routines without requiring any formal programming skills. Data entry and retrieval are extremely easy, as well as transfer of data between different software packages. This paper review some of the commonly used generic software packages, focusing on spreadsheets, data base programs, and integrated software packages for IBM PC compatible microcomputers.Several commercial programs, varying in price and capability, are evaluated to determine their applicability in environmental engineering calculations Evaluations were made in terms of the potential use in engineering calculations and other applications, the mathematical capacity, speed of calculations, versatility, and user friendliness. Data transfer between different programare extremely crucial for engineering applications. It is achieved by using “standard” file formats, such as SIF and DIF files.     

Keep talking—Performance effectiveness with continuous voice recognition for spreadsheet users

The performance of spreadsheet users was compared for two modes of input to the computer—keyboard and continuous voice recognition (CVR)—for subjects classified by their decision style. In addition, the data for this experiment was compared to results of a similar experiment that used a discrete word recognition system. Dependent measures were task completion time, accuracy, keystroke count, correction count, and user confidence for spreadsheet tasks. Results, using a speaker-dependent continuous voice recognizer, showed that for both simple data input and more complex analytical problems, subjects did not perform more effectively using CVR compared to keyboard. In addition, a subject's decision style was found not to interact with CVR for an effect on performance. Compared to earlier discrete word recognition results, CVR tended to shorten the time to complete a spreadsheet analysis task.     

Twinkling lights and nested loops: distributed problem solving and spreadsheet development

In contrast to the common view of spreadsheets as “single-user” programs, we have found that spreadsheets offer surprisingly strong support for cooperative development of a wide variety of applications. Ethnographic interviews with spreadsheet users showed that nearly all of the spreadsheets used in the work environments studied were the result of collaborative work by people with different levels of programming and domain expertise. We describe how spreadsheet users cooperate in developing, debugging and using spreadsheets. We examine the properties of spreadsheet software that enable cooperation, arguing that: (1) the division of the spreadsheet into two distinct programming layers permits effective distribution of computational tasks across users with different levels of programming skill; and (2) the spreadsheet's strong visual format for structuring and presenting data supports sharing of domain knowledge among co-workers.     

Keep talking—Performance effectiveness with continuous voice recognition for spreadsheet users

The performance of spreadsheet users was compared for two modes of input to the computer—keyboard and continuous voice recognition (CVR)—for subjects classified by their decision style. In addition, the data for this experiment was compared to results of a similar experiment that used a discrete word recognition system. Dependent measures were task completion time, accuracy, keystroke count, correction count, and user confidence for spreadsheet tasks. Results, using a speaker-dependent continuous voice recognizer, showed that for both simple data input and more complex analytical problems, subjects did not perform more effectively using CVR compared to keyboard. In addition, a subject's decision style was found not to interact with CVR for an effect on performance. Compared to earlier discrete word recognition results, CVR tended to shorten the time to complete a spreadsheet analysis task.     

Avoiding,finding and fixing spreadsheet errors – A survey of automated approaches for spreadsheet QA

Spreadsheet programs can be found everywhere in organizations and they are used for a variety of purposes, including financial calculations, planning, data aggregation and decision making tasks. A number of research surveys have however shown that such programs are particularly prone to errors. Some reasons for the error-proneness of spreadsheets are that spreadsheets are developed by end users and that standard software quality assurance processes are mostly not applied. Correspondingly, during the last two decades, researchers have proposed a number of techniques and automated tools aimed at supporting the end user in the development of error-free spreadsheets. In this paper, we provide a review of the research literature and develop a classification of automated spreadsheet quality assurance (QA) approaches, which range from spreadsheet visualization, static analysis and quality reports, over testing and support to model-based spreadsheet development. Based on this review, we outline possible opportunities for future work in the area of automated spreadsheet QA.     

Analysis of the Cognition Involved in Spreadsheet Software Interaction

This article analyzes details of the cognition involved when people use spreadsheet software, a task that is both a major microcomputer application and a cognitively intense task. This task is analyzed in terms of the GOMS model (Card, Moran, & Newell, 1983), to test the generality of the model and to extend its set of parameters. We found that people using two seemingly similar spreadsheet applications, Lotus 1-2-3 and Multiplan, require very different amounts of time to accomplish the same tasks. Experienced users of Lotus 1-2-3 took far longer to complete the same four tasks than experienced Multiplan users did. It was found that some of additional time was due to the fact that Lotus 1-2-3 offers users a choice of two general methods to enter formulas. Lotus requires that the user decide which to use; this decision takes time. And, when the users type the address of the cell in which values reside instead of using the cursor to point to it, they pause a long time before typing each entry. Presumably they are scanning the screen and calculating the coordinates to type in during the pause. Again, these cognitive processes take time. In an analysis of a second task-adjusting the column width-there was substantial evidence that the performance changes when a method is repeated in close succession. This repetition affects the parameters that reflect the time it takes to retrieve command parts from memory. When the parameters for scanning, decision, and repetition were added to the keystroke analysis of our task, we found remarkable correspondence with the basic parameters from the Card et al. (1983) original work: The keystroke times and mental preparation times from their original experiments were very close to the estimates of those same parameters in our tasks. However, in our analysis of the spreadsheet task, we expanded the parameter set in the keystroke model to account for performance in tasks that require substantial planning, scanning, and repetition.     

A mental model perspective for tool development and paradigm shift in spreadsheets

To address the problem of errors in spreadsheets, we have investigated spreadsheet authors׳ mental models in a hope of finding cognition-based principles for spreadsheet visualization and debugging tools. To this end, we have conducted three empirical studies. The first study explored the nature of mental models of spreadsheet authors during explaining and debugging tasks. It was found that several mental models about spreadsheets are activated in spreadsheet authors׳ minds. Particularly, when explaining a spreadsheet, the real-world and domain mental models are prominent, and the spreadsheet model is suppressed; however, when locating and fixing an error, one must constantly switch back and forth between the domain model and the spreadsheet model, which requires frequent use of the mapping between problem domain concepts and their spreadsheet model counterparts. The second study examined the effects of replacing traditional spreadsheet formulas with problem domain narratives in the context of a debugging task. Domain narratives were found to be easy to learn and they helped participants to locate more errors in spreadsheets. Furthermore, domain narratives also increased the use of the domain mental model and appeared to improve the mapping between the domain and spreadsheet models. The third study investigated the effects of allowing spreadsheet authors to fix errors by editing domain narratives, thus relieving them from the use of traditional low-level cell references. This scenario was found to promote spreadsheet authors using even more of their domain mental model in a manner that completely overshadowed the use of their spreadsheet mental model. Thus, from a mental model perspective, it is possible to devise a new spreadsheet paradigm that uses domain narratives in place of traditional spreadsheet formulas, thus automatically presenting spreadsheet content so that it prompts spreadsheet authors to think in a manner that closely corresponds to their mental models of the application domain.     

On recommendation problems beyond points of interest

Recommendation systems aim to recommend items or packages of items that are likely to be of interest to users. Previous work on recommendation systems has mostly focused on recommending points of interest (POI), to identify and suggest top-k items or packages that meet selection criteria and satisfy compatibility constraints on items in a package, where the (packages of) items are ranked by their usefulness to the users. As opposed to prior work, this paper investigates two issues beyond POI recommendation that are also important to recommendation systems. When there exist no sufficiently many POI that can be recommended, we propose (1) query relaxation recommendation to help users revise their selection criteria, or (2) adjustment recommendation to guide recommendation systems to modify their item collections, such that the users׳ requirements can be satisfied.We study two related problems, to decide (1) whether the query expressing the selection criteria can be relaxed to a limited extent, and (2) whether we can update a bounded number of items, such that the users can get desired recommendations. We establish the upper and lower bounds of these problems, all matching, for both combined and data complexity, when selection criteria and compatibility constraints are expressed in a variety of query languages, for both item recommendation and package recommendation. To understand where the complexity comes from, we also study the impact of variable sizes of packages, compatibility constraints and selection criteria on the analyses of these problems. Our results indicate that in most cases the complexity bounds of query relaxation and adjustment recommendation are comparable to their counterparts of the basic recommendation problem for testing whether a given set of (resp. packages of) items makes top-k items (resp. packages). In other words, extending recommendation systems with the query relaxation and adjustment recommendation functionalities typically does not incur extra overhead.     

Model inference for spreadsheets

Many errors in spreadsheet formulas can be avoided if spreadsheets are built automatically from higher-level models that can encode and enforce consistency constraints in the generated spreadsheets. Employing this strategy for legacy spreadsheets is difficult, because the model has to be reverse engineered from an existing spreadsheet and existing data must be transferred into the new model-generated spreadsheet. We have developed and implemented a technique that automatically infers relational schemas from spreadsheets. This technique uses particularities from the spreadsheet realm to create better schemas. We have evaluated this technique in two ways: first, we have demonstrated its applicability by using it on a set of real-world spreadsheets. Second, we have run an empirical study with users. The study has shown that the results produced by our technique are comparable to the ones developed by experts starting from the same (legacy) spreadsheet data. Although relational schemas are very useful to model data, they do not fit spreadsheets well, as they do not allow expressing layout. Thus, we have also introduced a mapping between relational schemas and ClassSheets. A ClassSheet controls further changes to the spreadsheet and safeguards it against a large class of formula errors. The developed tool is a contribution to spreadsheet (reverse) engineering, because it fills an important gap and allows a promising design method (ClassSheets) to be applied to a huge collection of legacy spreadsheets with minimal effort.     

Logical operators of some statistical computing packages and missing values

When using statistical computer packages in general, we rely on the results they produce. We are aware that numerical approximations are made and trust that the best algorithms are chosen to do them. Most manuals give us instructions about precision of calculations and some report how missing values are administered. What we are unaware of is that some packages can invent results when creating atomic formulas and compounding complex formulas out of atomic ones, what inflates sample sizes, and possibly leads us to incorrect statistical decisions. Two simple indicator variables, with missing values positioned so the results are always missing values, were tested as numerical, as logical and as character variables, by compounding them through connective ‘and’ (&) and ‘or’ (|) to form new indicator variables. The results show that one of the three very known packages does not, statistically, correctly handle missing values, and the three make atomic formulas out of character variables assigning the value false (0) for missing value, what can be said an statistical error. The conclusion is that statisticians and users of statistics must be aware of the capabilities of logically operating missing values of the statistical packages they use, otherwise wrong statistical decisions can be made. And that programmers of statistical packages should correct their algorithms in order to not permit their packages invent non-existing values.     

Learning performance and computer software: an exploration of knowledge transfer

Computer studies educators have a challenging task in keeping pace with the rapidly changing content of computer software. One way to meet this challenge is to examine the nature of knowledge transfer. Instead of focusing on unique software packages, teachers could concentrate on knowledge that is likely to transfer from one software application to another. The purpose of the current study was to describe what kind of knowledge is used in learning new software, assess the relative effectiveness of this knowledge in aiding the learning process, and examine how the results could advance educational learning theory and practice. Thirty-six adults (18 male, 18 female), representing three computer ability levels (beginner, intermediate, and advanced), volunteered to think out loud while they learned the rudimentary steps (moving the cursor, using a menu, entering data) required to use a spreadsheet software package (Lotus 1-2-3). Previous understanding of terminology, software concepts and actions, and other software packages had the largest impact, both positive and negative, on learning. A basic understanding of the keyboard and common movement keys was also important, although higher level knowledge (e.g., terms, concepts, actions) is probably necessary for significant gains in learning performance. Computer ability had little impact on the type of transfer knowledge used, except with respect to the use of software concepts and, to a lesser extent, terminology. The interaction between problem type and effectiveness of a specific transfer area suggests that identifying specific common tasks among software packages is important in detecting useful transfer knowledge. It is equally important that computer users understand labeling idiosyncrasies of these common tasks.     

Package Fingerprints: A visual summary of package interface usage

ContextObject-oriented languages such as Java, Smalltalk, and C++ structure their programs using packages. Maintainers of large systems need to understand how packages relate to each other, but this task is complex because packages often have multiple clients and play different roles (class container, code ownership, etc.). Several approaches have been proposed, among which the use of cohesion and coupling metrics. Such metrics help identify candidate packages for restructuring; however, they do not help maintainers actually understand the structure and interrelationships between packages.ObjectivesIn this paper, we use pre-attentive processing as the basis for package visualization and see to what extent it could be used in package understanding.MethodWe present the Package Fingerprint, a 2D visualization of the references made to and from a package. The proposed visualization offers a semantically rich, but compact and zoomable views centered on packages. We focus on two views (incoming and outgoing references) that help users understand how the package under analysis is used by the system and how it uses the system.ResultsWe applied these views on four large systems: Squeak, JBoss, Azureus, and ArgoUML. We obtained several interesting results, among which, the identification of a set of recurring visual patterns that help maintainers: (a) more easily identify the role of and the way a package is used within the system (e.g., the package under analysis provides a set of layered services), and (b) detect either problematic situations (e.g., a single package that groups together a large number of basic services) or opportunities for better package restructuring (e.g., removing cyclic dependencies among packages). The visualization generally scaled well and the detection of different patterns was always possible.ConclusionThe proposed visualizations and patterns proved to be useful in understanding and maintaining the different systems we addressed. To generalize to other contexts and systems, a real user study is required.     

Decisional guidance and end-user display choices

Powerful desktop computers with commercial spreadsheet and presentation software empower computer users to produce their own data displays, choosing from an ever-increasing variety of display formats. Although previous research has explored some organizational risks involved in end-user computing little is known, first, about the effects of shifting control over display choices from trained specialists to mainstream computer users and, second, whether end-users would benefit from decisional guidance in this area. We conducted an experimental study to gain insight into these issues by studying the display preferences and performance of student subjects in two different kinds of tasks. We found subjects performed certain tasks no better with their preferred display than with a randomly assigned display. Theory-based decisional guidance improved subjects' overall performance substantially, and subjects welcomed decisional guidance as long as it did not limit their options.     

The application of microcomputer data-base management packages in medical research

The role of microcomputer data-base management (DBMS) packages in the management of medical research studies has been reviewed. The features of commercial DBMS packages which are of particular advantage have been identified.A bench-mark test, resembling stages in the conduct of a research project, was constructed and four commercial packages compared in their performance of it. The packages varied in facilities offered, and it was found that the more sophisticated ones took longer to set up to perform the task. In use the less sophisticated packages were faster, but could become tedious to use with regular tasks and more error prone with complex tasks.The selection of a DBMS package depends on the potential application. This will involve a detailed assessment of the task to be performed: as a general rule a sophisticated package will only be warranted if the study is both complex and large. In practice research departments may benefit from more than one package.     

The Package Blueprint: Visually analyzing and quantifying packages dependencies

Large object-oriented applications are structured over many packages. Packages are important but complex structural entities that are difficult to understand since they act as containers of classes, which can have many dependencies with other classes spread over multiple packages. However to be able to take decisions (e.g. refactoring and/or assessment decisions), maintainers face the challenges of managing (sorting, grouping) the massive amount of dependencies between classes spread over multiple packages. To help maintainers, there is a need for at the same time understanding, and quantifying, dependencies between classes as well as understanding how packages as containers of such classes depend on each other.In this paper, we present a visualization, named Package Blueprint, that reveals in detail package internal structure, as well as the dependencies between an observed package and its neighbors, at both package and class levels. Package blueprint aims at assisting maintainers in understanding package structure and dependencies, in particular when they focus on few packages and want to take refactoring decisions and/or to assess the structure of those packages. A package blueprint is a space filling matrix-based visualization, using two placement strategies that are enclosure and adjacency. Package blueprint is structured around the notion of surfaces that group classes and their dependencies by their packages (i.e., enclosure placement); whilst surfaces are placed next to their parent node which is the package under-analysis (i.e., adjacency placement). We present two views: one stressing how an observed package depends upon the rest of the system and another stressing how the system depends upon that package.To evaluate the contribution of package blueprint for understanding packages we performed an exploratory user study comparing package blueprint with an advanced IDE. The results show that users of package blueprint are faster in analyzing and assessing package structure. The results are proved statically significant and they show that package blueprint considerably improves the experience of standard browser users.     

Programming by example: The human face of AI

It is argued that “human-centredness” will be an important characteristic of systems that learn tasks from human users, as the difficulties in inductive inference rule out learning without human assistance. The aim of “programming by example” is to create systems that learn how to perform tasks from their human users by being shown examples of what is to be done. Just as the user creates a learning environment for the system, so the system provides a teaching opportunity for the user, and emphasis is placed as much on facilitating successful teaching as on incorporating techniques of machine learning. If systems can “learn” repetitive tasks, their users will have the power to decide for themselves which parts of their jobs should be automated, and teach the system how to do them — reducing their dependence on intermediaries such as system designers and programmers. This paper presents principles for programming by example derived from experience in creating four prototype learners: for technical drawing, text editing, office tasks, and robot assembly. A teaching metaphor (a) enables the user to demonstrate a task by performing it manually, (b) helps to explain the learner's limited capabilities in terms of a persona, and (c) allows users to attribute intentionality. Tasks are represented procedurally, and augmented with constraints. Suitable mechanisms for attention focusing are necessary in order to control inductive search. Hidden features of a task should be made explicit so that the learner need not embark on the huge search entailed by hypothesizing missing steps.