TASK GUIDANCE FOR ORGANIZING AND
ANALYZING INVESTIGATION DATA
For Use During MES-Based Investigations
Table of Contents
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An investigator's next challenge is to organize the building blocks into a description of the process being investigated. This organization challenge generally stated is to:
Procedures for this task are contained in this Guide. They cover manual and software-supported procedures.
Guide 1 described how to look for and document ACTIONS as Event Blocks during an investigation. This Guide describes how to organize, relate and test MES Event Building Blocks (EBs) to identify INTERACTIONS. This task is required to develop an objective, consistent description and explanation of what happened.
All these functions take place on special actor/action matrixes, a key data organization and analysis element of the MES investigation technology. These matrixes provide for the progressive organization., display and analysis of data as the data are acquired during an investigation. As each new data item is added to the matrix, the description and explanation of what happened become more complete and coherent. MES matrixes introduce new opportunities to improve investigation efficiency, effectiveness, timeliness and value. This Guide describes the tasks required to prepare and quality check MES Matrixes.
MES Matrixes have many uses. They can be used to
This examples also show how the preparation of good Matrixes can contribute to a comprehensive organizational learning process based on efficient, objective, timely and integrated investigations of all kinds of occurrences in the organization or activity..
The objective of this Guidance is to explain how an investigator can organize and analyze investigation data by developing, testing and quality checking MES Matrixes. Matrixes are a progressive data organizing and analysis tool, with which an investigator can achieve consistent, valid work products efficiently and quickly. The Matrixes become "events flow charts" describing what happened. Ideally, an MES Matrix provides a description of an occurrence in a form that allows others to reproduce it, much like a musical score or an actor's script enables reproduction of a symphony or play. This Guide describes how to place, analyze, relate, test, and present observed or recorded data during investigations to arrive at complete, replicable, easily communicated and valid explanations of the occurrences.
Completed Matrixes describing what happened will look generally like Figure 2-1, which shows the progression of an process producing an accidental outcome. In Matrixes, each change event is an EB created from data observed and documented during the investigation.
Figure 2-1 General Appearance of MES-based Matrix.
EBs on the final Matrix have links to show interactive relationships among EBs that produced the outcome. Uncertainties, if any, are indicated with a "?" convention, either in the EB or along the links.
MES Matrixes can be used in all investigations, but they are most valuable during investigations of unprecedented, large, complicated or mysterious occurrences. For Level 1 investigations, they can be sketched to develop the narrative sections of forms. For Level 2 investigations, they facilitate a demonstration that the events are presented in logical sequence. For Level 3 investigations, they provide a basis for discovering and defining problems disclosed by the evidence For Level 4 investigations, they also help organize, direct and control the tasks of however many investigators are engaged in the investigation, and screen unsupported theories about what happened, as well as discipline speculations.
The MES Matrix can also be used to define new or existing system operations, and then analyze those systems for potential problems and action needs.
The MES Matrix organizes data investigators acquire, step-by-step in a progressive way that defines the remaining data still needed as the investigation progresses. This procedure accommodates all relevant data from observers, documents, and other things, as the data are acquired. The procedure specifies criteria investigators can use to identify data relevant or irrelevant to a specific investigation. The procedure determines whether or not data acquired is necessary and sufficient through a specified testing procedure.
Data acquired during an investigation must be recast into Event Building Blocks (EBs) before it can be used to build an MES matrix. Each new EB is placed on a Matrix as it is acquired, to capture and organize the data. Time and actor coordinates on the Matrix guide the placement of each EB relative to each other EB. Concurrent precede/follow and necessary/sufficient logic tests define the interactions among EBs required to produce the outcome of interest. When completed, the Matrix will describe what happened, and the interactions will define why it happened, with gaps in the EB flow showing remaining uncertainties.
Matrixes can be developed manually or on computers. Part I describes manual matrix development. Part II describes computerized development.
Remember, your goal is to develop a flow chart of what happened in a way that explains why it happened, using the data available. Remember also that you are using a dynamic matrix. By design, it will grow and contents may shift significantly over time as more data are acquired during an investigation. It is also a matrix that helps define additional questions to ask and data to seek as it develops.
Manual MES Matrix preparation procedures during investigations require:
1. Event Building Blocks created from the data acquired (See Guide 1).
2. A Matrix layout space, such as a large clear wall, large chalk board or a roll of butcher paper on which to lay out the EBs as they become available. A clear floor are can also be used.
3. A method for capturing the content of interim and completed matrixes, such as a camera, large xerographic or blueprint copier or coded EB filing scheme e.g., an alphanumeric designation of matrix intersection for each card.
4. If butcher paper is used, a marking pen or chalk to draw linking arrows between EBs; otherwise use masking tape for links.
Position EBs on the MES Matrix as they become available. There is no theoretical limit to the number of EBs you can add -if you can make room for them on your workspace. Manual implementation handles 30 actors easily, computers handle many more.
Select a work surface on which you will prepare your matrix. Prepare a name card (3M "POST-IT") for each actor named in any EB you put on the Matrix. Make a new name card containing only the actor's name as you make the first EB for any actor. Start the MES Matrix by placing all name cards in a column down along the left edge of your work surface. Place each EB into the row defined by the name card with the EB actor's name on Matrix.
Place each EB you create on the actor's horizontal row. Position it in its correct time and spatial sequence relative to all other EBs already on the Matrix. Expand the Matrix to the left or right when you add EBs, and down when you have to add an actor row.
Use the left edge of the EB to position the EB under the time it started. Keep the time scale flexible, and reposition the EBs as they are added to keep the relative timing intact throughout the investigation.
As each event is put into place on the actor's line, mentally compare the position of your EB against the next preceding EB and the next following EB on that row, to assure it is positioned in its correct time and spatial sequence.
Sometimes it becomes necessary to place a time line with tick marks along the top of part of the matrix, to ensure that the timing of events is distinguishable, or to show the role of time in the scenario. Any time line should be considered tentative until the final Matrix testing is completed.
This is the first of several logic tests for your matrixes. If the actor influenced subsequent actions during the occurrence (a change maker), or reacted to another actor/change maker by doing something, the EB may be relevant. As EBs are added, draw tentative arrows (lines with pointers) from one EB to any later EB that it changed. Linking EBs with arrows creates "EB pairs" or "events sets." Causal links between EB pairs may be shown in one of the following forms.
Figure 2-2. Causally-linked EB Sets
Precede/follow logic links may produce (1) causally-linked EB pairs, or (2) converging EB sets or (3) diverging EBs sets. Uncertainties are indicated by a question mark (?) between the EBs, as in (4). Uncertainties are not objectionable if they were pursued during the investigation, and if they are faithfully represented in the text of the report. (See also IQC procedure in Guide 10.)
If you can't draw links between EBs, the gaps between unlinked EBs point to potential unknowns in your understanding of what happened. Thus the Matrix defines what you need to find out as your investigation progresses. Where links are suspected to exist, an arrow with a ? shows uncertainty that should be a candidate for further investigation. The question marks can be used to assign investigation tasks as the investigation progresses, reducing the elapsed time for the investigation, and reducing investigation costs.
Try MES-Trees, (see Guide 3), simulations, tests or reenactments (see Guide 6) to bridge gaps in your logical EB flows if the gap prevents you from understanding and describing what happened and why it happened for your purposes.
7. Perform Necessary and Sufficient tests.
This procedure tests each EB set or pair to determine the sufficiency of the event flows represented to produce the occurrence outcome.
A Test each EB pair for the necessary relationship, then B test if linked EBs are sufficient to produce the right EB (event Z), then C review all the links on the matrix. Begin as follows, starting with the right-most EB set (the outcome) on the matrix. Follow the if-then questions on the decision tree procedure below for each EB pair on the matrix.(EB or Event Building Block is expanded term for Event Block or EB)
Upon completion of the Necessary and Sufficient testing procedures, you should remove all the extraneous, unlinked EBs and notations that are irrelevant to the description of what actually happened from the Matrix. What remains should be a network of linked EBs that lead from the first event in the scenario to the outcome. That network should be the fullest description possible from the observed data and structured hypotheses. The next step is to subject the finished matrix to a final quality control examination.A completed matrix will have these general elements, before the recommendation development process is undertaken
Upon completion of the final quality control steps and the signing of the Matrix by its developers, the Matrix is ready for subsequent uses.
The process of developing EBs, positioning them on the matrix, linking them and testing sets for cause-effect relationships is is supported by Investigation Catalyst software, from Starline Software Ltd. That software provides Tutorials, software help and rules the help investigators. However, users should be acquainted with the manual implementation described above to guide their use of the software.
Computer graphics applications have developed to the point that they can be used to create animated descriptions of the behavior of objects in accidents. In the aviation field, particularly, the behavior of an aircraft in flight has been reconstructed from fight data recorders and displayed as a computer-generated movie. In significant cases, where the behavior of objects is important to display, the "mental movie" created by the investigator can be "transferred" to a computer using these computer graphics animating applications. The displays can also be used to aid in hypotheses. Look for expended use of this capability in the future.
Once made, these animations of the occurrence can be used for training, design considerations, and other purposes.
Users are invited to provide feedback to the webmaster on software applications that would be useful to other users.
 See also Hendrick, K. and Benner, L., INVESTIGATING ACCIDENTS WITH STEP, Marcel Dekker Inc., New York, NY 1987. The acronym STEP (from Simultaneous Timed Events Plots) has been used to describe these matrixes. However, while descriptive of the format, STEP does not communicate the full breadth of functions served by the matrixes, so the broader term MES technology-based Matrixes or MES MATRIXS is the term of choice used in this set of Guides.
 The format shown in this Guide differs from the format presented previously, because these Guides distinguish the description development tasks separately from the needs and recommendation development tasks. A completed marked up matrix is illustrated in the Recommended Actions Development Guide 8.
 MES Matrixes differ from Events and Causal Factors (E&CF) charts because MES shows only actions - no conditions - on the matrix. Conditions do not produce the next change; the action(s) that produced the conditions produced it, and they should be the primary interest of the investigator. E&CF charts are technically obsolete today.